8 in all, mostly Swaledale members, attended this trip.
Apparently the owner is quite willing to allow cavers access, although it’s normally sold as a guided trip open to the public, with essential gear rental included (harness, 2 * long cow’s tails, tandem pulley (cable or speed variant, not rope). We stayed in the Plas Curig hostel, which is fine, but a bit pricey at £50 each for two nights in bunks in dorm rooms. There’s apparently a bunkhouse next door at £7 – but I’m assured it’s horrible.
There’s quite a few traverses which scare off some of the public customers, and there’s quite a few zip wires, including ‘the longest underground zip wire in the world’ (130m) – which is unavailable unless you have two official guides – but as it involves being lowered through a stop it’s not that exciting. There’s plenty of other zip wires though, mostly close to horizontal so no braking problems.
There’s something like 64 miles of passages, I believe – scope for quite a lot of exploration.
There’s also the Croesor / Rosydd through trip in the same area.
We were planning to do Rhiwbach Mine on the Sunday, but this was abandoned due to heavy snow – with one road closed, and a truly horrible walk-in with real prospect of finding ourselves snowed in later we decided to abandon.