Aled Williams - Bugail yr Enwau

Cwm Cneifion

Ychwanegiadau: Ffoes Wen, Rhiwiau’r Caws, Clogwyn Du, Creigiau Gleision, Blaen y Gribyn.

Dileadau: The Nameless Cwm and Cwm Cneifio, Gribin Facet, Sub-Cneifion Rib, Upper Cliff of Glyder Fawr.

Enwau lleoedd o gwmpas Cwm Cneifion.

Rhagymadrodd

Ers mis Hydref 2025, rwyf wedi bod yn gweithio gyda Pharc Cenedlaethol Eryri gyda’r nod o weithredu newidiadau i fapiau’r Arolwg Ordnans mewn perthynas ag enwau lleoedd Eryri. Gall hyn gynnwys ychwanegu enwau anghyhoeddedig, dileu enwau ffug, neu welliannau i gywirdeb lleoliadol a chyfansoddiadol. Fy rôl yn hyn yw darparu’r dystiolaeth ar gyfer y newidiadau, gan dynnu ar gronfa ddata helaeth yr wyf wedi’i chreu drwy arolygon lleol a gwaith ymchwil archifol ers 2012. Wedi cytuno gyda’r Parc ar yr argymhellion, dechreuir wedyn ar broses ymgynghorol gyda’r Arolwg Ordnans a Chomisiynydd y Gymraeg.

Mae’n bwysig fod gan yr Arolwg Ordnans broses i wirio newidiadau cartograffig, a hyn ar sail tystiolaeth gadarn. Fel arall, mae perygl i bob math o anghywirdebau a ffugenwau ymddangos ar fapiau, gan gyfrannu at erydiad diwylliannol. I wneud hyn yn effeithiol, dylid cynghori unigolion sydd â gwybodaeth arbenigol mewn toponomeg ac sydd hefyd wedi meithrin gwybodaeth leol, gan mor hawdd y gall gwallau godi pan fydd brwdfrydedd yn drech ar gofal dyladwy. Rhaid gwneud pob ymdrech i nodi ffynonellau cyfoes a hanesyddol fel y gellir cynnal gwerthusiad trylwyr i sicrhau bod unrhyw newid yn ddilys, o ran cywirdeb lleoliad a chyfansoddiad yr enw lle.

Y newidiadau blaenorol a dderbyniwyd gan yr Arolwg Ordnans yw:

Diffwys Criafol (Grŵp: Yr Wyddfa)

Ysgar (Grŵp: Yr Wyddfa)

Mae’r erthygl hon yn cyhoeddi’r dystiolaeth a gyflwynwyd i’r Arolwg Ordnans i gefnogi ychwanegu Ffoes Wen, Rhiwiau’r Caws, Clogwyn Du, Creigiau Gleision, a Blaen y Gribyn ar eu mapiau, ynghyd â dileu The Nameless Cwm, Gribin Facet, Sub‑Cneifion Rib, ac Upper Cliff of Glyder Fawr, yn ogystal â chywiro camleoliad yr enw Cwm Cneifio.

Byddaf yn postio’r canlyniad unwaith y clywir yn ôl gan yr Arolwg Ordnans, yn ôl pob tebyg yn ddiweddarach eleni.

Crynodeb

Cynigir nifer o ychwanegiadau i enwau lleoedd ar ochr ogleddol Glyder Fawr; cyfeiriwch at Ffigwr 1. Diffinnir yr ardal hon gan rhediad y Ffoes Wen yn y gorllewin a braich Y Gribyn yn y dwyrain. Mae’r llethrau sy’n disgyn o gopa Glyder Fawr tuag at Gwm Idwal yn cynnwys tair prif nodwedd: Rhiwiau’r Caws, sy’n serth a chreigiog; gwagle Cwm Cneifion, wedi’i ffinio gan y Clogwyn Du a Chreigiau Gleision; a’r darn isaf a elwir yn Flaen y Gribyn.

Ffigwr 1 – Detholiad o fap 1:25,000 yr Arolwg Ordnans yn arddangos yr enwau newydd.

Yn ogystal, argymhellir cywiro camleoliad yr enw Cwm Cneifio, ynghyd â dileu pedwar enw ffug a greuwyd gan aelodau’r gymuned ddringo ac a ychwanegwyd at fapiau graddfa‑fawr yr Arolwg Ordnans tua 1980; cyfeiriwch at Ffigwr 2. Y rhain yw The Nameless Cwm ar gyfer Cwm Cneifion, Gribin Facet ar gyfer Clogwyn y Tarw, Sub‑Cneifion Rib ar gyfer rhan o Flaen y Gribyn, ac Upper Cliff of Glyder Fawr ar gyfer rhan o Rhiwiau’r Caws – enwau a ddyfeisiwyd yn wreiddiol oherwydd absenoldeb yr enwau brodorol ar fapiau’r Arolwg Ordnans.

Ffigwr 2 – Detholiad o fap 1:25,000 yr Arolwg Ordnans yn arddangos yr enwau i’w dileu.

Y Dystiolaeth – Ychwanegiadau

Dyma’r dystiolaeth ar gyfer yr enwau lleoedd.

Ffoes Wen:

Mae Ffoes Wen wedi’i lleoli yng nghefn Cwm Idwal, yn y cyfeirnod grid SH 641 586, ac mae’n rhedeg o SH 641 583 i SH 643 591.

Daw’r cofnod cynharaf o fap o Gwm Idwal a gyhoeddwyd gan Gyngor Cefn Gwlad Cymru yn 1992, lle mae’n ymddangos fel ‘Ffos Wen’.

Mae’r cofnod dilynol yn deillio o arolwg lleol a gynhaliais yn 2013. Yn ystod yr arolwg hwn, cyfweliwyd y bugail lleol W. A. Williams, a nododd fod Ffoes Wen wedi’i lleoli yn SH 641 586, sef y nant sy’n ffinio ochr orllewinol Rhiwiau’r Caws ac sy’n llifo i Lyn Idwal, gan ffurfio rhaeadr tua’i chanol. Mae’r elfen gyntaf, ffoes, yn amrywiad lleol ar y gair ffos, a gydnabyddir gan Geiriadur Prifysgol Cymru.

Daw’r drydedd ffynhonnell o ymholiadau a wnaed gan E. Williams gyda’r bugail lleol W. O. Griffiths yn 2022, a enwyd yr un nodwedd ganddo fel Ffoes Wen.

Rhiwiau’r Caws a Chreigiau Gleision:

Rhiwiau’r Caws yw’r allt serth a chreigiog, gyda haenau o gerrig chwarts, wedi’i chanoli ar y cyfeirnod grid SH 644 587, ac yn ymestyn mewn lled o SH 642 586 i SH 646 588, ac mewn hyd o SH 644 584 i SH 644 589. Fe’i gelwir hefyd yn Llwybrau Caws, gyda’r haen mwyaf amlwg o gwarts yn cael ei alw’n Llwybr Caws.

Creigiau Gleision yw’r creigiau sy’n ffinio ochr orllewinol y grib a elwir Y Gribyn, gan ymestyn o’r cyfeirnod grid SH 649 584 i SH 650 590.

Dyddir y cofnod cynharaf ar gyfer Rhiwiau’r Caws a Chreigiau Gleision i 12 Medi 1727. Fe’u cofnodwyd gan y botanegwr Samuel Brewer (1670–1743), a gafodd yr enwau gan dywysydd lleol yn ystod un o’i sawl ymweliad â Chwm Idwal wrth chwilio am brwynddail y mynydd (Lloydia serotina) a rhywogaethau prin eraill o flodau arctig‑alpinaidd. Dyma ddyfyniad na chyhoeddwyd o’r blaen o ohebiaeth Brewer â’r botanegydd Johann Dillenius (1684–1747):

'on the 12 of Sept I went to Trigvylchau Rocks where I found in severall places great plenty Gnaphalium montnum...I found all these Rocks more than ordinary productive of curious plants & I think in a more thriving condition than any about Snowdon

Note that these Rocks faceth the South point of the Lake Llyn Idwel & mostly black & wet & there runneth a Rill of Water downe them that come from Llyn y Cwn & in the midle of them there is a notable cave where I found 2 sorts of pretty ffernes From those Rocks we have a view of the west end of Llyn Ogwyn & from thence I searched all the Rocks calld Rhiwau yr Caws halfe way up till I came opposite to the west end of Llyn Ogwyn still in search for Bulbosa Alpina for as Llyn Idwal lieth between Llyn y Cwn & Lyn Ogwyn & just under Trigvylchau Rock & Dr Richardson taking no notice of this midle Lake makes me think he had made some mistake in describing the place where he found Bulbosa alpina grew or his Guide not inform him rightly of the names of the places

Those Rocks that is east of Rhiwau yr Cawes is called Creigiau gleision & is also opposite & above Lyn Ogwyn

Note that the Rocks that you & I searched the 23rd of Augt in search for Bulbosa Alpina taking them for Trigvylcaugh Rocks wch lieth above Llyn Idwel & under the Top of the Glyder are called Llwybir y Caws'.

Ffigwr 3 – Detholiad o lythyr Samuel Brewer.

Mae’r ail gofnod yn ymddangos fel ‘Llwybr y Caws’ yn erthygl 1964, ‘The Names of Crags in Snowdonia: a First Report – Part 1’ gan J. Neill ac R. E. Hughes, The Climbers’ Club Journal, Cyf. XIV, Rhif 2 (Cyfres Newydd). Cafwyd yr enw hwn, ynghyd â’r wybodaeth ganlynol, gan y botanegwr ac gyn-warden Cwm Idwal, E. Roberts, yn ystod ei ymholiadau gyda’r gymuned ffermio leol:

‘This name (“cheese path”) is used today for the Quartz Platform on the upper cliff of Glyder Fawr’.

Daw’r trydydd cofnod o erthygl a ysgrifennwyd gan Bob Roberts, a ymddangosodd yn Bulletin of the Mountaineering Club of North Wales rywbryd yn ystod y 1970au neu’r 1980au, gyda’r wybodaeth ganlynol yn cael ei rhoi:

‘Llwybr Caws – This path runs well above the Holly Tree Wall across a scree and along the foot of Glyder Fawr cliff where the climbs are situated.’

Daw’r pedwerydd cofnod o fap o Gwm Idwal a gyhoeddwyd gan Gyngor Cefn Gwlad Cymru yn 1992, lle mae’n ymddangos fel ‘Llwybr y Caws’.

Mae’r bumed ffynhonnell yn cynrychioli nifer o gofnodion unigol gan fugeiliaid a gyfweliwyd gennyf yn ystod arolwg lleol yn 2013, sef E. Jones, M. Pritchard, G. P. Roberts, G. Thomas, a W. A. Williams. Dywedwyd y pump ohonynt mai Llwybrau Caws neu Llwybr Caws (y ffurfiau lluosog ac unigol yn cael eu defnyddio’n gyfartal) yw’r haenau o chwarts sy’n brithio’r allt serth a chreigiog rhwng Ffoes Wen a cheg Cwm Cneifion. Ychwanegasant fod yr haen fwyaf amlwg a llorweddol yn nodi llwybr sy’n arwain ar draws yr wyneb ac sy’n cael ei ddefnyddio wrth gasglu defaid, ac mai gwyn fel caws oedd y creigiau dan sylw.

Daw’r chweched ffynhonnell o ymholiadau a wnaed gan E. Williams gyda’r bugail lleol W. O. Griffiths yn 2022, a enwyd yr un nodwedd yn yr un modd, sef Llwybrau Caws.

Clogwyn Du:

Clogwyn Du yw’r clogwyn uchaf ar Glyder Fawr, wedi’i leoli wrth gyfeirnod grid SH 645 581. Ceir nifer o gofnodion sy’n perthyn i’r enw hwn, ac fe ymddangosodd gynt ar fapiau’r Arolwg Ordnans.

Priodolir y cofnodion cynharaf i’r botanegwr Edward Llwyd (1660–1709), yn ymddangos fel ‘Clogwyn du ymhen y Glyder’ ac ‘y Clogwyn du ymhen y Gluder’ yn argraffiad 1690 o Synopsis Methodica Stirpium Britannicarum gan John Ray, ac yn ddiweddarach fel ‘Klogwyn dû ymhen y Glyder’ yn argraffiadau Gibson o Britannia gan W. Camden yn 1722. Ymddengys i’r hynafiaethydd Thomas Pennant fabwysiadu’r ffurf olaf ar gyfer ei lyfr A Tour in Wales 1770.

Mae’r ail gofnod yn dyddio i 1741, gan ymddangos fel ‘Clogwyn du’ mewn catalog o blanhigion prin a luniwyd gan William Morris.

Yn 1901, cyhoeddwyd yr enw fel ‘Clogwyn Du’ ar fap chwe modfedd yr Arolwg Ordnans (Caernarvonshire XVII.SE).

Ffigwr 4 – Detholiad o fap chwe modfedd yr Arolwg Ordnans o 1901.

Y nesaf i gofnodi’r enw oedd y brodyr Abraham yn eu llyfr Rock-Climbing in North Wales (1906), gan ymddangos eu bod wedi cael yr enw yn uniongyrchol neu’n anuniongyrchol gan ffynhonnell leol:

‘The crags of the eastern face of Glyder Fawr are probably the grandest on the whole mountain. Geologists tell us that this great cliff, which is known locally as Clogwyn Du, differs from the rest of the Glyders in that it is composed of a mass of intrusive greenstone.’

Mae’r ffynhonnell olaf yn cynrychioli dau gofnod unigol gan fugeiliaid a gyfweliwyd gennyf yn ystod arolwg lleol yn 2013, sef E. Jackson a W. A. Williams. Enwyd y graig dan sylw gan y ddau dyst fel Clogwyn Du.

Blaen y Gribyn:

Blaen y Gribyn yw’r allt wrth gyfeirnod grid SH 647 591, hynny yw, y tir rhwng Llyn Idwal, Clogwyn y Tarw, a chefnen Y Gribyn.

Cofnodwyd yr enw hwn gyntaf yn sgil ymholiadau a wnaed gan E. Williams gyda’r bugail lleol G. Thomas yn 2024, a oedd yn adnabod y lle fel Blaen y Gribyn.

Yn 2026, fe wnes i ymholiadau annibynnol gyda G. Thomas, a gadarnhaodd yr enw a’i union leoliad. Eglurodd fod Blaen y Gribyn yn enw allweddol a ddefnyddid yn ystod y broses o hel defaid: man lle byddai’n rhaid i rywun sefyll er mwyn sicrhau bod y defaid yn symud i lawr o Bochlwyd i Gwm Idwal, yn hytrach na rhedeg i fyny tuag at Gwm Cneifion.

Y Dystiolaeth – Dileadau

Dyma’r dystiolaeth o blaid y dileadau.

The Nameless Cwm a Cwm Cneifio:

The Nameless Cwm a Cwm Cneifio a roddir i wahanol leoliadau ar fapiau cyfoes yr Arolwg Ordnans. Ymddengys y cyntaf fel Cwm Cneifion / The Nameless Cwm ar gyfer y cwm uchel wrth gyfeirnod grid SH 647 585, tra bo Cwm Cneifio yn cael ei roi mewn safle anghywir wrth gyfeirnod grid SH 630 585.

Y cofnod cyntaf yw’r ffurf gamysgrifenedig ‘Cwm Cynoddion’, a gofnodwyd gan yr Arolwg Ordnans rhwng 1816 a 1820 wrth gyfeirnod grid SH 630 585, sef 1.7 km i’r gorllewin o’r safle cywir.

Ffigwr 5 – Detholiad o fap drafft yr Arolwg Ordnans o 1816-1820.

Yr ail gofnod yw’r un a geir yn llyfr Hynafiaethau Llandegai a Llanllechid (1866) gan H. D. Hughes, lle cofnodir y ffurf lafar ‘Cwm Cnyfia’.

Yn 1899, cyhoeddodd yr Arolwg Ordnans eu map chwe modfedd cyntaf o’r ardal (Caernarvonshire Sheet XVII.SW), gan gadw’r anghywirdeb safleol o fap drafft 1816–1820, ond yn newid y ffurf i ‘Cwm Cynofiau’, sy’n cyfateb i’r ffurf ‘Cwm Cnyfia’ a gofnodwyd yn 1866. Adolygwyd y map chwe modfedd yn 1901, gyda’r ffurf yn cael ei newid unwaith eto i ‘Cwm Cneifio’. Ar ôl siarad â’r holl fugeiliaid a fu’n bugeilio’r tir hwn yn 2013, ni chlywodd yr un ohonynt yr enwau hyn yn gysylltiedig â’r lleoliad, gan ddweud wrthyf mai rhan o Gwm Padrig ydyw. O ganlyniad, argymhellir bod Cwm Cneifio yn cael ei ddileu o fapiau’r Arolwg Ordnans yn y lleoliad hwn, fel a ddangosir yn Ffigwr 2.

Oherwydd y gwall lleoliad a nodwyd uchod, ymddangosai’r cwm uchel wrth gyfeirnod grid SH 647 585 yn ddi-enw ar fapiau’r Arolwg Ordnans. Pan ysgrifennodd J. M. A. Thomson am ei ddringo yno yn 1905, yn yr erthygl ‘Reminiscences of First Ascents on the Glydr Fawr’, The Climbers’ Club Journal, Vol. VIII, No. 28, cydnabyddodd y diffyg hwn drwy gyfeirio ato fel ‘The Nameless Cwm’. Fodd bynnag, erbyn cyhoeddi ei lyfr Climbing in the Ogwen District yn 1910, roedd wedi darganfod yr enw brodorol: ‘Cwm Cneifion, hitherto called the Nameless Cwm’. Fel y datgelir yn y gohebiaeth a gyhoeddwyd yn The Climbers’ Club Journal, No. 1 (New Series), 1912, bugail oedd ei ffynhonnell:

Ffigwr 6 – Detholiad o ohebiaeth J. M. A. Thomson yn The Climbers’ Club Journal, 1912.

Y cofnod nesaf yw ‘Cwm Cneifia’ yn yr erthygl ‘The Names of Crags in Snowdonia: a First Report – Part 1’ (1964) gan J. Neill a R. E. Hughes, The Climbers’ Club Journal, Vol. XIV, No. 2 (New Series). Casglwyd yr enw gan y botanegwr a chyn-warden Cwm Idwal, E. Roberts, gan aelodau o’r gymuned ffermio leol.

Yn anffodus, parhaodd The Climbers’ Club i ddefnyddio The Nameless Cwm ochr yn ochr â Cwm Cneifion, gan arwain i’r ddau gael eu hychwanegu at fapiau graddfa fawr yr Arolwg Ordnans tua 1980.

Yn ystod 2013 a 2014, cyfweliais nifer o fugeiliaid a oedd yn adnabod enw’r cwm uchel wrth gyfeirnod grid SH 647 585, sef: J. Davies, E. Jackson, E. Jones, G. Jones, M. Pritchard, G. Thomas, a W. A. Williams. Rhoddwyd y ffurfiau canlynol i mi: Cwm Cnufiau (ar lafar Cwm Cnufia), Cwm Cneifiau (ar lafar Cwm Cneifa), a Cwm Cneifio, sydd, yn ôl pob tebyg, yn ffurf lafar o Cwm Cneifion. O’r sampl cyfoes hwn, defnyddiodd 43% Cwm Cnufiau, 43% Cwm Cneifiau, a 14% Cwm Cneifio / Cwm Cneifion. Mae’r ffurfiau hyn yn amrywiadau o’r un enw lle ac yn cynrychioli ansoddeiriau lluosog o’r enwau cnu, cnuf a cnaif.

O ganlyniad, argymhellir bod y label diangen The Nameless Cwm yn cael ei ddileu o fapiau’r Arolwg Ordnans, gan adael Cwm Cneifion yn ei le priodol fel enw brodorol y cwm, fel a ddangosir yn Ffigwr 2.

Gribin Facet:

Y clogwyn wrth gyfeirnod grid SH 650 596 a nodir ar fapiau graddfa fawr yr Arolwg Ordnans fel Clogwyn y Tarw / Gribin Facet. Gellir olrhain tarddiad Gribin Facet i’r arweinlyfr dringo Climbing in the Ogwen District (1910), lle mae’n ymddangos fel pennawd – ‘The Facet of The Gribin’ – nid oedd erioed yn fwriadol fel enw lle. Serch hynny, fe’i hychwanegwyd at fapiau’r Arolwg Ordnans tua 1980.

Ffigwr 7 – Detholiad o arweinlyfr Climbing in the Ogwen District, gan J. M. A. Thomson, 1910.

Fel a ddangosir yn Ffigwr 6, nid oedd awdur yr arweinlyfr, J. M. A. Thomson, yn disgwyl i bennawdau o’r fath gael eu hychwanegu at fapiau’r Arolwg Ordnans, ond roedd yn awyddus i gael enwau brodorol y clogwyni. Cyflawnwyd ei ddymuniad yn dilyn ei farwolaeth yn 1964, pan gafodd J. Neill a R. E. Hughes o The Climbers’ Club yr enw’n lleol fel Clogwyn y Tarw gan ‘Mr. Williams of Gwern y Gof Uchaf’, a’i gyhoeddi yn eu herthygl ‘The Names of Crags in Snowdonia: a First Report – Part 1’, The Climbers’ Club Journal, Vol. XIV, No. 2 (New Series). Yn anffodus, er bod Clogwyn y Tarw wedi’i ddefnyddio yn yr arewinlyfrau a gyhoeddwyd yn ddiweddarach gan The Climbers’ Club, fe’i cyflwynwyd fel Clogwyn y Tarw / Gribin Facet, sy’n egluro’r sefyllfa bresennol ar fapiau’r Arolwg Ordnans.

Yn ystod arolwg lleol a gynhaliais yn 2013, enwyd y clogwyn hwn yn Clogwyn Tarw gan ddau fugail lleol, sef E. Jones a G. Thomas.

Argymhellir felly fod Gribin Facet yn cael ei ddileu o fapiau’r Arolwg Ordnans, gan adael Clogwyn y Tarw yn ei le priodol fel enw brodorol y clogwyn, fel a ddangosir yn Ffigwr 2.

Sub‑Cneifion Rib:

Sub‑Cneifion Rib yw enw dringfa a ddringwyd gyntaf gan J. M. Edwards yn 1931, ac a ymddangosodd yn yr arweinlyfr Climbing Guides to the Snowdon District: III – Glyder Fach, gan C. F. Kirkus, a gyhoeddwyd gan The Climbers’ Club yn 1937. Lleolir y ddringfa ar un o’r creigiau bychain ar yr allt a elwir Blaen y Gribyn. Er mai enw dringfa yn unig ydy Sub‑Cneifion Rib, fe’i hychwanegwyd at fapiau graddfa fawr yr Arolwg Ordnans tua 1980.

Ffigwr 8 – Detholiad o arweinlyfr Climbing Guides to the Snowdon District: III – Glyder Fach, gan C. F. Kirkus, 1937.

Argymhellir bod enw’r ddringfa Sub‑Cneifion Rib yn cael ei ddileu o fapiau’r Arolwg Ordnans, a’i ddisodli gan yr enw brodorol Blaen y Gribyn, fel a ddangosir yn Ffigyrau 1–2.

Upper Cliff of Glyder Fawr:

Ychwanegwyd y label Upper Cliff of Glyder Fawr at fapiau graddfa fawr yr Arolwg Ordnans tua 1980, wrth gyfeirnod grid SH 643 584, ar sail cynnwys sy’n perthyn i lenyddiaeth ddringo. Gellir olrhain ei darddiad i 1934, pan gyfeiriodd y dringwr J. M. Edwards ato’n syml fel ‘Upper Cliff’ yn ei erthygl ‘Young Climber’, The Climbers’ Club Journal, Vol. V, No. 1 (New Series). Yn 1936, cyhoeddodd Edwards yr arweinlyfr, Climbing Guides to the Snowdon District: I – Cwm Idwal Group, a gyhoeddwyd gan The Climbers’ Club, lle labelwyd y clogwyn yn amrywiol fel ‘Upper Cliff’, ‘Upper Cliff Glyder Fawr’, ‘Upper Cliff, Glyder Fawr’, ac ‘The Upper Cliff of the Glyder Fawr’.

Mae’r label yn gamarweiniol, gan nad dyma’r clogwyn uchaf ar Glyder Fawr – Clogwyn Du yw hwn, ym mhen uchaf Cwm Cneifion. Mewn gwirionedd, defnyddir Upper Cliff of Glyder Fawr i gyfeirio at hanner uchaf yr allt serth a chreigiog a elwir Rhiwiau’r Caws.

Argymhellir felly fod Upper Cliff of Glyder Fawr yn cael ei ddileu o fapiau’r Arolwg Ordnans, a’i ddisodli gan yr enw brodorol Rhiwiau’r Caws, fel a ddangosir yn Ffigyrau 1–2.

Cydnabyddiadau

Diolch o galon i J. Davies, W. O. Griffiths, E. Jackson, E. Jones, G. Jones, M. Pritchard, G. P. Roberts, G. Thomas, a W. A. Williams am sicrhau bod eu gwybodaeth enwau wedi’i chofnodi er mwyn y dyfodol.

Diolchir hefyd i E. Williams, E. Owain, I. Wyn, N. Jones ac R. Wheldon‑Roberts am eu hymroddiad, eu hannogaeth a’u cefnogaeth.

Cydnabyddaf hefyd y canlynol fel ffynonellau ar gyfer y ffigurau a ddefnyddir yn yr erthygl: Arolwg Ordnans, The Climbers’ Club, British Library, National Library of Scotland, a Bodleian Libraries, University of Oxford.

Aled Williams, Awst 2026.

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Ordnance Survey Changes:

Cwm Cneifion

Home

Proposed Additions: Ffoes Wen, Rhiwiau’r Caws, Clogwyn Du, Creigiau Gleision, Blaen y Gribyn.

Proposed Deletions: The Nameless Cwm and Cwm Cneifio, Gribin Facet, Sub-Cneifion Rib, Upper Cliff of Glyder Fawr

The place-names about Cwm Cneifion.

Introduction

Since October 2025, I have been working with Eryri National Park with the aim of effecting changes to Ordnance Survey mapping in relation to the place‑names of Eryri. These changes may include the addition of previously unpublished names, the deletion of non‑native names, and positional or compositional corrections. My role is to supply the evidential basis for such changes, drawing on an extensive database that I have built through local place‑name surveys and archival research since 2012. Once proposed changes are agreed with Eryri National Park, a consultative process then begins with Ordnance Survey and the Welsh Language Commissioner.

Cartographic changes are rightly scrutinised by Ordnance Survey, and their appropriateness must be demonstrated by compelling evidence. Without a vetting process, there is potential for all manner of erroneous or invented place-names to appear on maps, each contributing to the cultural erosion of a locality. Such changes are best guided by those with expertise in toponymy who have also acquired local knowledge, since errors are easily introduced when enthusiasm overrides due diligence or when educated guesses are allowed to replace facts. Every effort must be made to identify contemporary and historical sources so that a thorough evaluation can be undertaken to ensure that any change is valid, both in terms of positional accuracy and place-name composition.

Previous changes accepted by Ordnance Survey are:

Diffwys Criafol (Group: Yr Wyddfa)

Ysgar (Group: Yr Wyddfa)

This article serves to publish the evidence submitted to Ordnance Survey in support of the additions of Ffoes Wen, Rhiwiau’r Caws, Clogwyn Du, Creigiau Gleision, and Blaen y Gribyn, together with the deletions of The Nameless Cwm, Gribin Facet, Sub‑Cneifion Rib, and Upper Cliff of Glyder Fawr, as well as the correction of the erroneous positioning of Cwm Cneifio.

I will post the result once we hear back from the Ordnance Survey, most likely later in the year.

Summary

A number of native place‑name additions are proposed for features located on the northern side of Glyder Fawr; refer to Figure 1. The western extent of this area is defined by the cascading stream of Ffoes Wen, while its eastern limit is marked by the ridge known as Y Gribyn. The slopes descending from the high plateau of Glyder Fawr towards Cwm Idwal comprise three major features: the steep, rocky hillside of Rhiwiau’r Caws; the hanging valley of Cwm Cneifion, bounded by the crags of Clogwyn Du and Creigiau Gleision; and the lower hillside known as Blaen y Gribyn.

Figure 1 – Extract from the Ordnance Survey 1:25,000 map annotated to show the proposed place-name additions.

Also recommended is the correction of the erroneously positioned Cwm Cneifio, together with the removal of four non‑native names devised by members of the climbing community and added to large‑scale Ordnance Survey mapping circa 1980; refer to Figure 2. These incongruous additions are The Nameless Cwm for Cwm Cneifion, Gribin Facet for Clogwyn y Tarw, Sub‑Cneifion Rib for a part of Blaen y Gribyn, and Upper Cliff of Glyder Fawr for a part of Rhiwiau’r Caws – all of which were originally invented to compensate for the absence of their native names on Ordnance Survey mapping, a purpose that may now be considered redundant.

Figure 2 – Extract from the Ordnance Survey 1:25,000 map annotated to show the proposed place-name deletions.

The Evidence - Additions

Here is the evidence for the proposed place-name additions.

Ffoes Wen:

Ffoes Wen is the watercourse centred at grid reference SH 641 586, running from SH 641 583 to SH 643 591.

The first known record comes from a map of Cwm Idwal published by the Countryside Council for Wales in 1992, where is appears as ‘Ffos Wen’.

The subsequent record derives from a local place-name survey I conducted in 2013. During this survey, I interviewed local shepherd W. A. Williams, who informed me that Ffoes Wen is located at grid reference SH 641 586, being the watercourse that flanks the western side of Rhiwiau’r Caws and flows into Llyn Idwal, forming a cascade at its midpoint. The first element, ffoes, is a local variant of Welsh noun ffos (ditch, gutter), as recognised by Geiriadur Prifysgol Cymru (A Dictionary of the Welsh Language).

The third source derives from enquiries made by E. Williams with local shepherd W. O. Griffiths in 2022, who likewise named the same feature as Ffoes Wen.

Rhiwiau’r Caws and Creigiau Gleision:

Rhiwiau’r Caws is the steep, rocky hillside marbled with quartz, centred at grid reference SH 644 587, extending in breadth from SH 642 586 to SH 646 588, and in length from SH 644 584 to SH 644 589. It is also known locally as Llwybrau Caws, with the most prominent band of quartz referred to as Llwybr Caws.

Creigiau Gleision are the crags flanking the western side of the ridge known as Y Gribyn, stretching from grid reference SH 649 584 to SH 650 590.

The earliest record for Rhiwiau’r Caws and Creigiau Gleision is dated 12 September 1727. They were documented by the English botanist Samuel Brewer (1670-1743), who obtained the names from a local guide during one of his several visits to Cwm Idwal in search of Snowdon lily (Lloydia serotina) and other rare arctic-alpine flora. The following is a hitherto unpublished extract from Brewer’s correspondence with the German botanist Johann Dillenius (1684-1747):

Those Rocks that is east of Rhiwau yr Cawes is called Creigiau gleision & is also opposite & above Lyn Ogwyn

Figure 3 – Extract from a letter written by Samuel Brewer.

The second record appears as ‘Llwybr y Caws’ in the 1964 article ‘The Names of Crags in Snowdonia: a First Report – Part 1’ by J. Neill and R. E. Hughes, The Climbers’ Club Journal, Vol. XIV. No. 2 (New Series). This name, together with the following information, was obtained from the local farming community by botanist and former warden of Cwm Idwal, E. Roberts:

‘This name (“cheese path”) is used today for the Quartz Platform on the upper cliff of Glyder Fawr’.

The third record comes from an article written by Bob Roberts, which appeared in the Bulletin of the Mountaineering Club of North Wales at some point during the 1970s or 1980s, with the following information given:

‘Llwybr Caws – This path runs well above the Holly Tree Wall across a scree and along the foot of Glyder Fawr cliff where the climbs are situated.’

The fourth record comes from a map of Cwm Idwal published by the Countryside Council for Wales in 1992, where is appears as ‘Llwybr y Caws’.

The fifth source represents multiple individual records from shepherds whom I interviewed during a local place‑name survey in 2013, namely E. Jones, M. Pritchard, G. P. Roberts, G. Thomas, and W. A. Williams. All five informants identified Llwybrau Caws or Llwybr Caws (the plural and singular forms being in equal use) as the bands of quartz rock that marble the steep, rocky hillside between Ffoes Wen and the mouth of Cwm Cneifion. They added that the most prominent and horizontal band marks a path leading across the face that is used when gathering sheep, and that the rocks in question were white like cheese.

The sixth source derives from enquiries made by E. Williams with local shepherd W. O. Griffiths in 2022, who likewise named the same feature as Llwybrau Caws.

Clogwyn Du:

Clogwyn Du is the highest precipice of Glyder Fawr, located at grid reference SH 645 581. The name is well attested and previously appeared on Ordnance Survey mapping.

The earliest records for this name are attributable to the botanist Edward Llwyd (1660-1709), appearing as ‘Clogwyn du ymhen y Glyder’ and ‘y Clogwyn du ymhen y Gluder’ in the 1690 edition of John Ray’s Synopsis Methodica Stirpium Britannicarum, and later as ‘Klogwyn dû ymhen y Glyder’ in Gibson’s edition of Camden’s Britannia in 1722. Antiquarian Thomas Pennant appears to have adopted the latter record for his book A Tour in Wales 1770.

The second record dates to 1741, appearing as ‘Clogwyn du’ in a catalogue of rare plants compiled by William Morris.

In 1901, the name was published as ‘Clogwyn Du’ on the Ordnance Survey six-inch map (Caernarvonshire Sheet XVII.SE).

Figure 4 – Extract from the Ordnance Survey six-inch map of 1901.

Next to record the name were the Abraham brothers in their 1906 book Rock-Climbing in North Wales, evidently having obtained the name directly or indirectly from a local source:

The final source represents two individual records from shepherds whom I interviewed during a local place‑name survey in 2013, namely E. Jackson and W. A. Williams. Both informants named the crag in question as Clogwyn Du.

Blaen y Gribyn:

Blaen y Gribyn is the hillside centred at grid reference SH 647 591, i.e. the land between Llyn Idwal, Clogwyn y Tarw, and the ridge of Y Gribyn.

This name was first recorded following enquiries made by E. Williams with local shepherd G. Thomas in 2024, who knew this place as Blaen y Gribyn.

In 2026, I made independent enquiries with G. Thomas, who confirmed both the name and its precise location. He explained that Blaen y Gribyn was a key name used during the process of gathering sheep: a place where a gatherer would need to stand to ensure that sheep moved down from Bochlwyd to Cwm Idwal, rather than drifting upwards towards Cwm Cneifion.

The Evidence - Deletions

Here is the evidence for the proposed place-name deletions.

The Nameless Cwm and Cwm Cneifio:

The Nameless Cwm and Cwm Cneifio are applied to different places on current Ordnance Survey maps. The first appears as Cwm Cneifion / The Nameless Cwm for the hanging valley centred at grid reference SH 647 585, while Cwm Cneifio is applied at an incorrect position at grid reference SH 630 585. The chequered history of these names is detailed below.

The first record is a misspelt ‘Cwm Cynoddion’, which the Ordnance Survey recorded between 1816 and 1820, and applied to grid reference SH 630 585, which is 1.7km west of the true position.

Figure 5 – Extract from the Ordnance Survey draft map of 1816-1820.

The second record is from the 1866 book Hynafiaethau Llandegai a Llanllechid by H. D. Hughes, where the colloquial form ‘Cwm Cnyfia’ is recorded.

In 1899, the Ordnance Survey published the first six-inch map of the area (Caernarvonshire Sheet XVII.SW), maintaining the erroneous position of the 1816-1820 draft map but revising the composition to ‘Cwm Cynofiau’, which corresponds to the ‘Cwm Cnyfia’ form recorded in 1866. The six-inch map was revised in 1901, with the name updated to ‘Cwm Cneifio’. Having spoken to all the shepherds who worked this land in 2013, none had heard of these names being connected to this location, informing me that this spot was simply a part of Cwm Padrig. As such, it is recommended that Cwm Cneifio be removed from Ordnance Survey mapping at this position, as shown in Figure 2.

Due to the positional error detailed above, the hanging valley centred at grid reference SH 647 585 appeared nameless on Ordnance Survey mapping. When climbing pioneer J. M. A. Thomson first wrote about his climbs there in 1905, in the article ‘Reminiscences of First Ascents on the Glydr Fawr’, The Climbers’ Club Journal, Vol. VIII. No. 28, he acknowledged this absence by referring to it as ‘The Nameless Cwm’. However, by the time Thomson published his guidebook Climbing in the Ogwen District in 1910, he had acquired the real name as ‘Cwm Cneifion, hitherto called the Nameless Cwm’. His source was a shepherd, as revealed in the following correspondence published in The Climbers’ Club Journal, No. 1 (New Series), 1912:

Figure 6 – Extract from J. M. A. Thomson’s correspondence in The Climbers’ Club Journal, 1912.

The next record is for ‘Cwm Cneifia’ in the 1964 article ‘The Names of Crags in Snowdonia: a First Report – Part 1’ by J. Neill and R. E. Hughes, The Climbers’ Club Journal, Vol. XIV. No. 2 (New Series). This name was obtained from the local farming community by botanist and former warden of Cwm Idwal, E. Roberts.

Unfortunately, subsequent guides published by The Climbers’ Club unnecessarily retained the use of The Nameless Cwm side-by-side with Cwm Cneifion, resulting in both being added to large-scale Ordnance Survey maps circa 1980.

During 2013 and 2014, I interviewed a number of shepherds who knew the name of the hanging valley centred at grid reference SH 647 585, namely: J. Davies, E. Jackson, E. Jones, G. Jones, M. Pritchard, G. Thomas, and W. A. Williams. The following forms were given: Cwm Cnufiau (colloquially Cwm Cnufia), Cwm Cneifiau (colloquially Cwm Cneifa), and Cwm Cneifio, which is probably a colloquial form of Cwm Cneifion. Out of this contemporary sampling, 43% used Cwm Cnufiau, 43% used Cwm Cneifiau, and 14% used Cwm Cneifio/ Cwm Cneifion. All are valid variants of the same place-name and represent plurals of the related Welsh nouns cnu, cnuf (fleece) and cnaif (fleece, a shearing).

It is therefore recommended that the redundant label The Nameless Cwm be removed from Ordnance Survey mapping, thus leaving Cwm Cneifion in its rightful place as the true name of the valley, as shown in Figure 2.

Gribin Facet:

The cliff at grid reference SH 650 596 is marked on large-scale Ordnance Survey maps as Clogwyn y Tarw/ Gribin Facet. The origins of Gribin Facet can be traced to the 1910 guidebook Climbing in the Ogwen District, where it appears as a heading – ‘The Facet of The Gribin’ – and was never intended as a place-name. Nevertheless, it was added to Ordnance Survey maps circa 1980.

Figure 7 – Extract from J. M. A. Thomson’s guidebook Climbing in the Ogwen District, 1910.

As shown in Figure 6, the guidebook’s author J. M. A. Thomson did not expect that such book headings would be added to Ordnance Survey mapping, but was eager to obtain the actual names of the crags. His wish was fulfilled posthumously in 1964, when J. Neill and R. E. Hughes of The Climbers’ Club obtained the name locally as Clogwyn y Tarw from ‘Mr. Williams of Gwern y Gof Uchaf’, which they published in their article ‘The Names of Crags in Snowdonia: a First Report – Part 1’, The Climbers’ Club Journal, Vol. XIV. No. 2 (New Series). Regrettably, although Clogwyn y Tarw was thereafter used in guidebooks produced by The Climbers’ Club, it was presented as Clogwyn y Tarw / Gribin Facet, which ultimately led to its addition to Ordnance Survey maps.

During a place-name survey I conducted in 2013, two local shepherds named this crag as Clogwyn Tarw, namely E. Jones and G. Thomas.

It is recommended that Gribin Facet be removed from Ordnance Survey mapping, thus leaving Clogwyn y Tarw in its rightful place as the true name of the cliff, as shown in Figure 2.

Sub-Cneifion Rib:

Sub-Cneifion Rib is the name of a climbing route first ascended by J. M. Edwards in 1931, and published in The Climbers’ Club guide Climbing Guides to the Snowdon District: III – Glyder Fach by C. F. Kirkus in 1937. The climb is located on one of the small outcrops on the hillside known as Blaen y Gribyn. Despite being merely the name of a climb, Sub-Cneifion Rib was added to large-scale Ordnance Survey maps circa 1980.

Figure 8 – Extract from C. F. Kirkus’s guidebook Climbing Guides to the Snowdon District: III – Glyder Fach, 1937.

It is recommended that the climb-name Sub-Cneifion Rib be removed from Ordnance Survey mapping and replaced by the genuine place-name Blaen y Gribyn, as shown in Figures 1-2.

Upper Cliff of Glyder Fawr:

The label Upper Cliff of Glyder Fawr was added to large-scale Ordnance Survey maps circa 1980 at grid reference SH 643 584, having been taken from climbing literature. Its origins can be traced to 1934, when climber J. M. Edwards referred to it simply as ‘Upper Cliff’ in his article ‘Young Climber’, The Climbers’ Club Journal, Vol. V. No. 1 (New Series). In 1936, Edwards authored The Climbers’ Club guide Climbing Guides to the Snowdon District: I – Cwm Idwal Group, in which the crag was labelled variably as ‘Upper Cliff’, ‘Upper Cliff Glyder Fawr’, ‘Upper Cliff, Glyder Fawr’, and ‘The Upper Cliff of the Glyder Fawr’.

The label is in fact a misnomer, since it is not the highest cliff on Glyder Fawr – that distinction belongs to Clogwyn Du, which is higher up at the top of Cwm Cneifion. In reality, Upper Cliff of Glyder Fawr is applied to the upper half of the rocky hillside known as Rhiwiau’r Caws.

It is recommended that Upper Cliff of Glyder Fawr be removed from Ordnance Survey mapping and replaced by the genuine place-name Rhiwiau’r Caws, as shown in Figures 1-2.

Acknowledgments

Sincere gratitude is owed to J. Davies, W. O. Griffiths, E. Jackson, E. Jones, G. Jones, M. Pritchard, G. P. Roberts, G. Thomas, and W. A. Williams for ensuring that their place-name knowledge was recorded for posterity.

Special thanks are also due to E. Williams, E. Owain, I. Wyn, N. Jones, and R. Wheldon-Roberts for their dedication, encouragement and support.

I also acknowledge the following as sources for the figures used in this article: Ordnance Survey, The Climbers’ Club, British Library, National Library of Scotland, and Bodleian Libraries, University of Oxford.

Aled Williams, August 2026.

Aled Williams -
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Newidiadau Arolwg Ordnans / Ordnance Survey Changes: Cwm Cneifion