Chartist Cave (or sometimes Chartist's or Chartists' Cave) is a culturally significant cave on

Mynydd Llangynidr Mynydd Llangynidr is a mountain in the Brecon Beacons National Park largely in the county of Powys, south Wales. Its southern slopes extend into the northernmost parts of the county borough of Blaenau Gwent. It is named from the village of Llangyn ...

in southern

Powys Powys (; ) is a Local government in Wales#Principal areas, county and Preserved counties of Wales, preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh succession of states, successor state, petty kingdom and princi ...

, Wales. The entrance is a broad arch formed of

Twrch Sandstone The Marros Group is the name given to a suite of rocks of Namurian age laid down during the Carboniferous Period in South Wales. These rocks were formerly known as the Millstone Grit Series but are now distinguished from the similar but geographi ...

('Millstone Grit') which overlies the

Carboniferous Limestone Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian Epoch of the Carboniferous Period. These rocks formed between 363 ...

immediately beneath.

The cave

The cave is located at about north-northeast of the village of

Trefil Trefil is a small village in the county borough of Blaenau Gwent, south Wales. It lies at the top of the Sirhowy Valley, near to Brecon Beacons National Park. It is three miles northwest of Tredegar. With one public house, The Top House, serving ...

at an elevation of about , at OS grid reference SO 127152 (51.8286 degrees North, 3.2672 degrees West). The entrance to Chartist Cave is high on the moors near the summit of

. The arched entrance is formed by a

('Millstone Grit') cap from beneath which the underlying

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...

has been eroded. The cave is also known by two different names in

Welsh Welsh may refer to: Related to Wales * Welsh, referring or related to Wales * Welsh language, a Brittonic Celtic language spoken in Wales * Welsh people People * Welsh (surname) * Sometimes used as a synonym for the ancient Britons (Celtic peopl ...

: Ogof Fawr (the 'Big Cave') and earlier as Tylles Fawr (the 'Great Hole'). The more commonly used modern name derives from 1839 when Chartist rebels used the cave to stockpile weapons in advance of their march on Newport in November of that year. There is a plaque at the entrance commemorating the Chartists' actions. Digging by the Severn Valley Caving Club, in 1969 and 1970, led to the discovery of a passage dropping to a lower chamber with many passages leading off. The known length of the cave is but it is believed to form a part of a much more extensive cave system beneath the moors. In the cave were found a

clay pipe Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay parti ...

, a flat perforated stone, and both animal and human bones. The stone may have been of considerable antiquity, but the human bones were thought to be between fifty and one hundred years old. The cave is included in the Mynydd Llangynidr Site of Special Scientific Interest designated in August 2012 by the

Countryside Council for Wales The Countryside Council for Wales (CCW; cy, Cyngor Cefn Gwlad Cymru (CCGC)) was a Welsh Assembly sponsored body responsible for wildlife conservation, landscape and countryside access authority for Wales. It was merged with Forestry Commiss ...

on the basis of the karstic landscape found here.

References

External links

guide to the cave

images of the cave on Geograph website
{{coord, 51.83123, N, 3.27119, W, type:landmark_region:GB, display=title Caves of Powys Sites of Special Scientific Interest in Brecknock