They are indeed the airlock at the exit, with double doors and a keeper at each door to ensure lemurs don't wander out. I guess they were the architects interpretation of a Madagascan native village hut. They have various signs and also viewing windows on 1 side looking into the open air/moated enclosure.
Thanks guys I thought that was what they are but it seams an odd addition, I thought they looked strange on the architects plans, they don't look to sturdy either. I'm sure it will look better when the planting grows in.
