Ogof Clogwyn

Summary

Ogof Clogwyn is a popular novice-friendly cave, and deservedly so. This is an easy and pleasant stream cave with attractive rock shelving, ideal for anyone wanting a shorter trip. There’s also an optional round trip for those wanting more of a challenge. The trip can also be combined with a visit to the nearby caves of Ogof Nant Rhin or Shakespeare’s Cave.

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Photos by Andy Watson, Emyr Walters and Matt Voysey

Location

NGR: SO 21299 12388 – what3words: ///tomato.fulfilled.opposite – Length: 352m

Ogof Clogwyn is located on the south side of the Clydach Gorge and the closest parking is at Gellifelen (NGR: SO 21484 12122, what3words: ///croak.spit.tidal). The easiest route there is to head to the village of Clydach (on the opposite side of the A465 Heads of the Valleys Road to Llangattock), then follow Quarry Road as it contours round the hill passing the car park and cycle trail at Llanelly Quarry. At a hairpin bend, follow the signs for Gellifelen, then turn right at the next junction (which has a post box). At the next fork shortly after, turn left into Long Row and continue on this road until a large layby for parking is reached on the left. The historic Gellifelen tunnels are located in the woodland just behind the car park, and these are also well worth a visit while you’re in the area.

Alternatively, if you don’t mind a longer walk, parking in the cycle trail car park at Llanelly Quarry is an option. From here you can follow the cycle trail/footpath on the opposite side of the road. This becomes a wide grassy track and meets the entrance to the disused Gellifelen railway tunnels after about 15 minutes. This tunnel is 320m long and provides an interesting route to the car park described above, which is just a few metres from the exit.

From the car park continue along the road a short distance until a bollard is met blocking vehicular access beyond. Look for a gate on the right here, this leads to a purpose built footpath which descends through the woodlands to the cave entrance in the Clydach Gorge below. This is often used by outdoor pursuits groups who use the large eyebolts alongside the path to rig a safety line to the cave.

Description

Ogof Clogwyn is easily recognisable by the waterfall issuing from its entrance. A short easy climb up gains the stream passage, which soon becomes walking height with exceptional phreatic shelving providing the option to traverse above the water. The first features passed are a short oxbow and tube to a high-level window in cliffs on ledges to the right, while a hole in the wall opposite is where the round trip rejoins the streamway. The next oxbow and tube on the right lead to the smaller and more awkward alternative entrance, which can be used on the way out for variety. A boulder pile on the left at a distinct bend in the passage 60m further marks the 4m climb up to the Upper Series and the round trip, but it makes sense to visit the end of the cave first and do this on the way back. The stream passage continues as easy walking before lowering to meet a sump after approximately 70m. A side passage on the right just before the end soon meets a second smaller sump.

The Upper Series and Round Trip – The climb up at the bend gains a tall rift passage heading back towards the cliff face. This is on two levels and a drop down near the start is the route to the round trip, while traversing along the wider section above continues for 50m, passing through some constrictions, to reach a small chamber with daylight entering through small gaps. The Upper Series ends with a small muddy chamber 10m beyond.

From the drop down, the round trip starts as a low crawl at the bottom of the rift before turning to the left. More crawling, some of which through puddles, soon leads to the window passed earlier where a short climb down regains the streamway.