I visited three UK zoos with some British zoo friends following my USA visit: Chester, Twycross and Colchester. Regrettably it was my first time with a digital camera; both cards were full of photos from the USA and I was only able to take few photos in the UK. I still need to do a proper UK zoo tour.
A former Gorilla exhibit, which used to house Chester's Eastern Lowland Gorillas. See below comment from SMR.
Yes, on the south-west aspect of the Tropical Realm, although the gorillas would have long-since departed when you visited as is evident from the vegetation and drained moat. The last gorilla at Chester departed in 1986. Both eastern lowland and western lowland were kept (1960-1985 and 1964-1986 respectively).
The area has been used for a number of other species since, the most popular being buffy-headed capuchin. Although the location was too busy and noisy for them, it made good use of the islands and moat. Currently the area houses red river hog and is little more than mud, the islands and moat have gone.
The indoor enclosures remain largely untouched however, and are now large hornbill aviaries.