South Wales Caves

Dan Yr Ogof Cave Description

Dan Yr Ogof is located near the head of the Swansea Valley (map) and the first part of the Cave along with Cathedral Cave and Bone Cave form part of a Dan Yr Ogof Showcaves tourist attraction. An interactive survey of the cave, now including video from some sections can be found on this page. The Showcave ends at Bridge Chamber, where the cavers' route - see DYOCAC website for access details takes you across a series of deep lakes and cascades to a climb out of the water at Lake 4. These lakes were first passed in 1937 and the next section of cave is known as the 1937 series. A magnificent formation is seen in the passage above Pot Sump. From here the route takes you left towards Boulder Chamber where you can enter Wigmore Hall or climb up a loose and dangerous boulder slope to gain access to the August Series, a set of high level rifts and chambers. From Boulder Chamber the route takes you past Lavatory Dan, a periodic syphon and on to Straw Chamber where a diversion to Corbels Chamber through a low crawl can be taken. From Straw Chamber you pass the entrance to Ashford Prices Hall and under the Showerbath to take you to the Horse Trough and the start of the Long Crawl. This Crawl first passed at Easter 1966 leads to the top of a fixed ladder pitch into Gerard Platten Hall and the start of DYO II.
Following the small stream you soon arrive at a parting of the ways on a major fault in the cave. Descending with the flow of water takes you to the Lower Series, while continuing along the main passage leads to the Crystal Pool. Using the stepping stones at the side of the Crystal Pool takes you to a rope traverse that leads to Flabbergasm Oxbow, noted for its distinctive shaped passage and ceiling to floor straws. This passage ends about 10m above the Grand Canyon and a return is made via the same route you came in. From the Crystal Pool the Grand Canyon leads off and in many places is festooned with helictites and straws. Near its end are the Candlewax Formations just before you break out into the massive passages of Monk Hall. This passage can be followed until it breaks out into Cloud Chamber named after the clouds of straws that cover the roof of this chamber. A small stream flows along the floor and following it to its source - Cascade Aven leads you to the climb up to the start of the Green Canal. At the start of the Green Canal a climb up a slope on the left leads into Hanger Passage where a route through a boulder choke takes you into a continuation that splits into Hanger North and Hanger South, both eventually choking. Back at the Green Canal a 50m swim making use of the buoyancy aids provided takes you to the final section of this passage where you wade until you reach Trenchways. To the left Trenchways leads to Avalanche corner and the top of the Abyss, while to the right is Go Faster that leads towards the Far North. As its name suggests progress is rapid through Go Faster until the passage divides at the start of Go Slower. The sandy passage to the left here ends in a squeeze through to Surprise Chamber. Go Slower starts as traverses in a rifty passage and soon reaches the Rottenstone Avens where passages to the right lead to Windows Aven and Tunnel Two. Following the main passage leads to Bat Chamber at the start of a larger passage that passes Bog Passage on the right before it ends at a sump pool at The Rising. A fixed ladder at The Rising leads to a very exposed climb up into Birthday Passage a high level passage and traverses that leads to a pitch down into the Great North Road.
The passage is now linear following a major fault in the cave an progress is fast as you head up through a boulder collapse and the entry to Pinnacle Chamber. North Bypass now takes you to the Meanders, past the impressively decorated Mostest to lead you to the bottom of North Aven. North Aven is a 17m free climb up a rock face following a fissure, in the central section there are fewer hand and footholds. This brings you to a passage that leads to the Starting Gate where two ways lead off, to the right is the aptly named Right Hand Series, while to the left leads to the Grand Hall and the Far North Chokes, the current limit of exploration of this cave.
Returning back to the Abyss a rope climb take you over the edge and down to the Elephant Hutch a very polished tube that now has a fixed stainless steel ladder in place. From the bottom of the Abyss you pass rope climbs up to Dalis Delight and to A1 Chamber before arriving at the Camel. A choice off two routes are available here, a polished climb over the hump or a tight crawl at the base following a small stream. This leads you to Thixatropic Passage named after the glutinous mud in its lower reaches. This continues until a fine cascade appears out of the roof just above a climb down to the entrance pool to Mazeways. Mazeways is a fine set of phreatic passages that are only accessible in periods of drought when the entrance pool lowers enough to allow access. The passage now heads to Lake 10 and from there to the start of Bakerloo Straight a fine section of phreatic tube. At the end of Bakerloo Straight a series of passages and climbs are followed to the left heading to the sound of water pounding in the Washing Machine. Traversing around this foaming mass of water leads you up the sandy floored passage to the start of Virgin Passage. A climb down gour pools takes you into some partly flooded passages where you wade across the pools. This ends above a pot that leads down to Lake 8, keeping to the left a passage is taken that leads to a small waterfall. Climbing this waterfall and following the passage above takes you back to Gerard Platten Hall and your route as you came into the cave.