At first I thought the middle planted area was just for decoration and I concentrated on the glassed in side exhibits. But as I was about to leave, I noticed there were live birds in that planter in the middle. I guess the skylight and plants keep them in the middle, because there were no barriers to keep them out of the rest of the room (yet they did not venture out). The building entrance (directly behind where I am standing) did NOT have double doors like most free flight aviaires.