Caves beneath the Black Mountain range
Experienced cavers can explore substantial lengths of passage and magnificent chambers decorated with stalactites and stalagmites deep beneath the Black Mountain, in the western part of the Brecon Beacons National Park.
Walkers on the mountain above Dan-yr-Ogof can follow the course of the upper Afon Giedd to a point where the river sinks into its bed at (SN811180). Sinc-y-Giedd is the principal sink for the Dan-yr-Ogof cave system. Another impressive swallow hole also feeding water into this system is that at Waen Fignen Felen (SN826177).
At the west end of the Black Mountain range, the Afon Llwchwr emerges dramatically from the limestone at Llygad Llwchwr (SN669178), a major resurgence, visible from a public foopath which passes nearby which provides water for the Brecon Carreg bottling company. This very wet cave was one of the first to be systematically explored when back in the 1840s Thomas Jenkins of Llandeilo took a rope ladder and collapsible coracle into the cave.
There are a handful of other small caves in the west, the largest of which are in the Herbert’s Quarry area and include Ogof Foel Fawr and Ogof Pasg. Of most interest to the casual visitor is the cave accessible from within Carreg Cennen Castle which is itself perched on top of a magnificent limestone crag. This natural cave passage may have served as a water supply for the castle’s former occupants. Torches can be hired at the farm when paying the castle entrance fee.