Ogof Pen Maelor description

Description credits

Author
Mark "Tarquin" Wilton-Jones, Brynmawr Caving Club.

Updates

Last updated: 20-Feb-2007

Location

Abersychan, South Wales, U.K.

Length
~80 metres (of which 70.6 metres surveyed B.C.R.A. grade 3c)
Depth
6.91 metres
Entrance grid reference
SO 2793:0449
Entrance altitude
315 metres

The cave is situated on a forest track on the south side of the Nant Maelor valley, east of Abersychan. It is to the south of the reservoir near the top of Waterworks Lane (the road up the valley).

No control is placed over access.

Survey

B.C.R.A. grade 3c survey has been conducted by the Brynmawr Caving Club (M W-J, I W-J, P W-J, P S J), and can be downloaded from this site.

Description

The cave has been blocked off (the blockage can be removed) at the two metre drop to prevent passing children from vandalising the cave and/or causing unnecessary rescues.

The cave is the easterly of two holes, and is the larger. This is usually walled up. The entrance hole leads immediately to a walking sized passage but this chokes after only 5 metres. About half way along this, on the left side of the passage, a two metre hole between boulders (now blocked with rocks but these can be cleared) in the floor leads to a junction.

Back under the entrance passage is the hole into Crystal Mushroom, while heading away from the entrance passage is a crawling sized passage, The Rat Run. Immediately, The Rat Run swings left. Continuing ahead, a side passage leads through a very tight squeeze into a small chamber, with a dead end rift ahead and a too tight side passage to the left leading back into The Rat Run.

Continuing along the Rat Run, the passage passes over a small boulder then swings right again and continues as a crawl. This ends after 7 metres at a fork where to the right chokes immediately and to the left leads up a slope through a squeeze into a large main chamber.

To the right is a 1 metre drop into three short crawls. Opposite the way in is a crawl into a very loose chamber, carrying a faint draught from an impossibly tight rift. To the left of the crawl is a hole down into a short passage, now covered with rocks. To the left in the main chamber is a prominent slanting rift. This is about 7 metres long and has many side passages which are too tight to enter. Where the rift splits, a climb up to the right leads into a 3 metre long flat out crawl, while to the left closes down immediately.

The hole into Crystal Mushroom leads down to Nemesis Rift, a very tight descending rift (very difficult on the return and only negotiable by small cavers) into a chamber, the start of Crystal Mushroom, so named for its large collection of botryoids. To the right, at the far side, is a difficult climb up into a short choked passage, with a faint voice connection with the westerly entrance, while to the left, a low crawl leads past many botryoids to another junction, all ways off being choked after about 5 to 7 metres.

The westerly hole consists of a 3 metre crawl to a bend right with a too tight continuation. This has a faint voice connection with a passage in Crystal Mushroom.

Disclaimer

Whilst every care has been taken in the compilation of this cave description, neither the author nor his fellow cavers can accept responsibility for loss or injury arising from any errors, omissions or inaccuracies in this cave description.

This description is subject to copyright. The copyright resides with the author and some other contributors. You are welcome to download, store, retransmit, print and distribute this document PROVIDED THAT (1) you do not do so for any form of reward, financial or otherwise, and (2) all references to the author are retained or otherwise clearly acknowledged. Any infringement of these conditions is an offence in the UK and also in most other countries.

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©1995-2007 MWJ