A CURIOUS orang-utan climbed out of its cage in 2003, forcing hundreds of visitors to take refuge in the restaurant, tropical house and cafes.

The orange ape spent about 90 minutes sitting on the roof of the enclosure but later lowered itself back into the cage and went to sleep.

An investigation revealed the animal had, over several days, lifted and removed roofing tiles to the enclosure, which housed five other orang-utans.

TRAGICALLY, in 1996 an escaped chimpanzee was shot dead as it attacked a keeper.

After an anaesthetic dart failed to knock out the 30-year-old ape another keeper fired the shot that killed the chimpanzee.

A BULL elephant went berserk after escaping the confines of the elephant enclosure and smashing through the zoo’s perimeter fence 26 years ago.

The animal got as far as Caughall Road, a mile away from Chester Zoo, before it was shot dead.