This is a fairly large exhibit, as I can just see a sun bear towards the back that lends some scope to the size of the enclosure. The new Asian-immersion, rainforest section of the zoo is quite impressive.
Yes, the Sunbear exhibit is surprisingly large for such a small zoo. Far better than most I've seen. I've not seen many good Sunbear enclosures given how active they can be - they do need a bit of room to wander around in.
