Ogof y Daren Cilau
| Ogof y Daren Cilau | |
| Brecknockshire | |
|---|---|
 Caver crawling into entrance | |
| SO20521530 | |
| Co-ordinates: | 51°49’50"N, 3°9’17"W |
| Depth: | 630 feet |
| Length: | 17 miles |
| Access: | free |
Ogof y Daren Cilau is one of several cave systems in the Llangattock escarpment near Crickhowell in the Brecon Beacons of Brecknockshire.
The cave's awkward entrance crawl of 565 yds is a natural barrier to any casual visitor and precludes the need for a locked gate to protect it from vandals.
Highlights of Daren Cilau include the Time Machine, the largest cave passage in Britain; the White Company, a set of pure white stalactites; and the Bonsai Tree, a branching helictite.
Due to the extent of the passages several miles from the entrance which would require trips of up to 20 hours to explore, two permanent underground camps have been established: the Hard Rock Café, and the Restaurant at the End of the Universe.
The major breakthrough into the system beyond the entrance series occurred in 1984, before which the cave consisted of little more than the entrance series and several uninspiring passages.
In 1986 Martyn Farr connected the Terminal Sump to Elm Hole in the next valley by cave diving.[1]
After decades of work and numerous cave digging projects, a connection to the nearby cave Ogof Agen Allwedd is yet to be found.