Dan yr Ogof

Dan yr Ogof , at the National Showcaves Centre for Wales, is a long cave system in south Wales, about north of Ystradgynlais and southwest of Brecon, in the Brecon Beacons National Park. It is the main feature of a show cave complex, which is claimed to be the largest in the United Kingdom and is a tourist attraction in Wales. The first section of the cave system is open to the public, but the extensive cave system beyond is scheduled as a national nature reserve and is open only to bona fide cavers.