The Otter and Owl Park used to have a collection of british reptiles in the pens that now hold mink, and also a few amphibian species in a vivarium built into one of the 'banks' in the glasshouse (this since been removed, but you can see where it is by making out the frame and glass viewing filled in with mud, it now surrounds a few plants) under the park's previous management as NatureQuest. When I had a discussion with the then-head keeper John Crooks a couple of years ago, he said the simple reason they didn't keep herps anymore was that the manager simply didn't like them.
Had any lynx arrived yet when you visited? They've been expecting a female to replace the late Oden for a while now.