Reid Park Zoo has an interesting entrance, and this photo shows it from a position already inside the zoo. A massive shade structure dominates the landscape, and there is a sleek, modern feel to the architecture. There isn't anything historic as the zoo was only founded in 1965, and there aren't any African thatched huts which seems to be the case at several other American zoos. To me it almost appears to be the entrance to an aquarium, as it seems to have a slippery, shiny facade.
It was designed to match the covering of a city parks therapeutic pool, which is directly across from the zoo entrance. On special night events, they use projectors to shine colored shapes (stars, animals, etc) onto the awning.
Not the most naturalistic entrance, but it is nicer looking than a lot of zoos. (Although this overlooked area - zoo entrances - seem to finally be addressed with several exciting new redos, such as Cincinnati and Seatlle and Phoenix).