I visited the Philly Zoo today and just wanted to say how much I love the McNeil Avian Center. I am not a huge bird lover as I generally do not spend much time looking at bird exhibits when I am on the outside looking in, but this exhibit is one of the better zoo experiences I have had. It's an extremely environment with birds flying all over the place, walking right by visitors, and interacting with each other of course. And as a visitor, you are right in the middle of the action.The birds themselves are beautiful and the exhibit is very well planted/landscaped, which makes it a great place for picture taking. The rhinoceros hornbills in the background are also really cool (I wish they had more space though) and the other 4 aviaries are also well done, with one containing no barriers. To sum up, I think this is an elite exhibit and is as enjoyable as any aviary I have visited including those at San Diego simply due to sheer volume of activity in there and the visitors proximity to it.