Porth yr Ogof (Entrance to the Cave) has the largest entrance in Wales, at 17m wide and 5m high. Actually it has many entrances, because it is formed where the Afon Mellte (Lightning River) flows for 200m through a huge limestone bridge. It splits in two before it goes underground, but emerges as a single stream. There is also an entrance which takes you to the underground river, and many entrances in the river banks. There is a small but entertaining network of passages which are all quite open and interconnected, so it will be easy to explore while maintaining distance. You are never more than 10 minutes from the outside, so it is safe to split into small groups and do mini trips. Further downstream are the famous waterfalls. So the whole area is very interesting, attractive, exciting, and speleologically significant. The trip is suitable for all, including children, whether you want to walk, cave, or just have a splash around and a picnic. Full wetsuit is recommended if you want to enter the water. Extreme caution is required in deep water. If in any doubt, wear buoyancy aids or DO NOT ENTER! There is a car park which costs £4 per car, but sometimes the attendant very generously tells cavers not to pay.
The idea will be to take a look at the tunnel entrance at the pub (if no-one’s seen it before) before taking a walk through the woods above the tunnel, walking along the line of the tunnel shafts below. If we have enough people to make up 2 groups, then we can stagger the timings of the groups going off etc etc.
Due to the current restrictions there will not be the GSS BBQ available & all are expected to bring their own food if they wish, but the pub ought to be open afterwards for a drink etc outside on the grass (very pleasant).
The various links below will give you some history of the canal and the tunnel, which at one point was the longest of its type in Britain:
Please let us know if you intend to come…