Its funny you should say that Jackwow. On my 1 and only visit to South lakes safari zoo when the keepers entered the enclosure to hang the meet on the poles for the feeding display, there was a ladder already inside the fence. Guess what............it was chained and padlocked to the fence!!
I know they have their fair share of animal escapees but I wasn't aware of snow leopards being able to lift a set of ladders up to a fence and then climb out the enclosure.