Ogof Craig a Ffynnon

A popular and well-decorated cave in the Clydach Gorge, only a short drive from Whitewalls. Though not connected to Daren and Aggy, Ogof Craig a Ffynnon is undoubtedly part of the same cave system, but with the bonus of wonderful cave formations that are far more easily reached. The Hall of the Mountain King is especially impressive.


Access is available to any bona fide caving clubs with membership to BCA or similar body. Information rescued in 2019 from the currently offline MLCMAC (Mmyndd Llangatwg Cave Management Advisory Committee) website is available below. Please note that some of this information is slightly out of date, but the contacts and access procedures are still valid:

CSS members can access the cave at any time using the club keys held at Whitewalls.

Location and Survey

NGR: SO 22011 12873 - what3words: ///hinted.commit.risking

Ogof Craig a Ffynnon is just a short drive from Whitewalls. The best way to get there is drive along the tramroad (Hafod Road) to the end, then at the roundabout opposite the new Gateway Bridge take the first exit along the Old Abergavenny Road. Continue along this road until you reach a layby overlooking the A465 where there should be space to park (NGR: SO 21745 12709 - what3words: ///mercy.fizzle.worlds).

From the layby walk a short distance further down the road to the ‘Clydach’ sign next to an old limekiln, where you’ll see the track to the cave heading off to the left. Follow the rough path weaving through the scrub into the quarry for some distance, the cave entrance is easy to spot being an obvious large open alcove in the quarry walls on the left above a boulder slope. The gated entrance is located at the rear of the rock alcove, and great care should be taken not to loiter here longer than necessary as numerous rock falls have occurred in the area. The gate should be locked after entering and the key is also required to exit the cave.  

The cave entrance to the left of Ogof Craig a Ffynnon with a rope to the entrance is Pope’s Hole, an abandoned dig of 10m length which does not connect with the main cave.

Warning: Craig a Ffynnon is liable to flood in heavy rain. The stream passage near the entrance can fill to the roof in wet weather and the first 90m of North-West Inlet is also flood prone.

Survey (click for larger version)

Route Descriptions

Hall Of The Mountain King

This is the usual destination for first-time visitors to Craig a Ffynnon and the trip involves a bit of everything from ladders, climbs and squeezes to large chambers and impressive formations.

Route Description

North-West Inlet

This starts with some very deep water and progress down the initial streamway can be very cold, but the reward is the impressively large passage beyond and ‘The Dragon’.

Route Description

The Promised Land and Helictite Passage

Beyond the Hall of the Mountain King, further squeezes and crawling eventually leads to much larger passage and fine formations in Helictite Passage, and ‘The Pagoda’ in the Promised Land.

Route Description