In reply to glaramara:
Bolting is quite good and there are names (but not grades, I think) painted under many of the routes.
Access depends on the river being low, and you should be aware that the river may rise rapidly at any moment... it may be prudent for the belayer to clip into the bottom bolt!
It's also good fun to mess around on some of the via-ferrata in the gorge, although some parts are broken / closed so take care. The wire ladder up through the roof of the cave is pretty cool, and you can also abseil off a hanging ladder bridge into the middle of the river. If it opens again it might be worth paying for... especially for the zipline over a waterfall in a cave.