Ardal Prif Gynnwys

Ogof y Siartwyr

Mae Ogof y Siartwyr mewn bryncyn amlwg i’r dwyrain o’r Garn Fawr ar rostir agored Trefil Las yn SO 1276 1523.  Ymddengys mai enw gwreiddiol yr ogof oedd Tylles Fawr. Yn 1809, daeth yr ogof i sylw Theophilus Jones, awdur History of Brecknockshire:
 
“In the Tir voel Glas is a natural cavern, the entrance into which is much larger and higher than that into Eglwys faen in Llangattock:  it presents a kind of arched room or vault, forty or fifty feet in circumference, and at the further end where the rock dips is a passage, leading perhaps to other appartments; it is generally known by the corrupted Welsh name of Stabl Fawr, or the great stable, because the little hilly horses, cattle and sheep are frequently known to run into it for shelter from the storm.” (Jones 1809, 517)

Ymddengys fod enwogrwydd yr ogof wedi ei seilio ar draddodiad lleol cryf iddi gael ei defnyddio fel ffatri arfau a man cyfarfod dirgel yn y cyfnod yn arwain at Derfysg y Siartwyr yn 1839. Cofnodwyd y traddodiad gyntaf gan Evan Powell yn 1884:

“1839 will be a memorable date, as the year in which the Chartists rose and made a march to Newport.  Preparations were made a long while previously; caves in Llangynider mountains were utilised as smitheries for the purpose of forging “pikes” and other weapons.” (Powell 1902, 57)

Rhaid dweud fod Oliver Jones, hanesydd uchel ei barch am Syrhywi a Tredegar yn amheus am wirionedd y traddodiad neilltuol hwn:

“About this time [Gorffennaf 1839], the Chartists of Sirhowy and Tredegar began using the cave on Mynydd Llangynidr. Why they went there and what they did there has never been satisfactorily explained. It has been suggested that the place was used as a smithy for the making of pikes and other weapons but this is hardly true; why go to such an out-of-the-way spot to make pikes when they could be secretly made in dozens in the Iron Works - as they were.  Again, no smith could live with the smoke of a forge in that unthinkable place which is now known as the Chartist Cave but was originally called ‘Tylles Fawr’. Inside at the end of a tunnel it opens out into a chamber-like cavern in the centre of which is a large stone rather like a table. This seems to suggest that the place was used for other purposes in days gone by. The entrance has now crumbled badly, making access both difficult and dangerous.” (Jones 1969, 97)

Fodd bynnag, pan dyllwyd yr ogof yn 1970 gan aelodau o Glwb Ogofa Dyffryn Hafren dan gyfarwyddyd R. G. Lewis, pibell glai a charreg wastad dyllog. Mae’n bosibl fod y garreg o gryn oed. Awgrymodd gwybodaeth ar yr esgyrn dynol a gyflwynwyd mewn cwest (gan Dr Bernard Knight), eu bod yn gymharol ddiweddar (50-100 mlwydd oed). Credir fod yr esgyrn wedi dod o leiaf dri unigolyn. Roedd un asgwrn clun wedi ei ddarnio, gan adael y posibilrwydd i’r esgyn gael eu claddu ar ôl un neu fwy o ddigwyddiadau lleol (RCAHMW 1997).  A oedd y rhain yn gyrff y Siartwyr a gariwyd adref o’r gyflafan a’i gladdu yma yn y dirgel? Ai dyma wir ystyr Ogof y Siartwyr? Mae’n debyg na fyddwn byth yn gwybod.

Llyfryddiaeth
Jones, O. 1969. The Early Days of Sirhowy and Tredegar (Rhisga: Cymdeithas Hanesyddol Tredegar).
Jones, T. 1809.  The History of Brecknockshire, Cyfrol II, rhan ii.
Powell, E.  1902. History of Tredegar (Casnewydd: South Wales Argus)
RCAHMW 1997 An Inventory of the Ancient Monuments in Brecknock (Brycheiniog); The Prehistoric and Roman Monuments, Part I, US 101 vii.