In reply to kmsands:
I'd describe it more as urban exploring than caving, I would say don't take ropes (at least nothing more than a bit of scramblers confidence cord for emergency) because you don't want to get tempted to use it and get into trouble on a first trip, with your daughter. There is a walk in down an incline that is wide, like 3 rail tracks wide and a lot to explore. Don't get clever and try to go down one incline and back up another, retrace steps carefully (unless you have a plan/survey etc and experienced). The place is draughty so you don't need to worry about air, just wear a helmet, have emergency torch, walk carefully don't trip up or fall down something. Tell someone where you went and a callout time. Enjoy...
If your daughter is adventurous.. and the above caught your attention then in the same area there is the Croesor to Rhosydd through trip ("CRTT"), that's a classic and worth a trip to Wales just for that alone. She will need to be able to abseil (1*25m and 1*20m) and prussic up a rope (8m) or in unplanned emergency prussic back up the abseils. If she can do that go on that instead. I would take a kid on that trip if (only if) they are sensible and can be self sufficient for short periods, I plan to take my son soon.
It is brilliant. Fixed ropes in place so you need carry a rope for emergency but likelihood of needing it is close to zero. Pull up and inspect all fixed rope for damage before you abseil on it. You will need harnesses and a lanyard on the harness (cows tail) with krab on the end, better 2 lanyards. Spare battery for headtorch as it is expected 4 to 6 hours, emergency torch, packed lunch, work or gardening gloves, helmet, wellies are perfect far better than walking boots as the tunnel out may be wet, big sense of adventure. It is a whole day activity. Park at Tanygrisiau SH 683 454 very close to Blaenau Ffestiniog.
Google it, loads of step by step instructions for that. Many are old and there is no longer a zipwire, you walk a tight steel cable for feet and tight steel cable for hands instead (clip cows tail, wear work gloves). The Canadian canoe (you need for one section) is still in there and contains a couple of spare buoyancy aids, but they'll probably be wet This could be a trip to remember!!!
Enjoy
Edit a better link
Post edited at 10:12