If you book outside of the school holiday's then they're not too bad. It's more than double the price during the school holidays and even the activities themselves can be more expensive.

I really enjoy the "no cars" rule they have, so all the little roads through the forest is used by people on bikes, and it's nice and peaceful.

We went to the one at Whinfell Forest in Cumbria. I'm not sure what the others are like but apparently it's got one of the best pools.