Wow, what a great idea. I just built a huge on in my latest zoo. It has a large crocodile enclosure, a komodo enclosure and a tortoise one. I accidentally built it a little too short. I couldn't put any trees in it! So, i built a hole, about 5 by 3 squares, about each enclosure, to allow some sunlight, and to allow room for a couple of trees in each enclosure.
You recindled my love of elevated paths. I can't wait to combine your reptile houses with tanks!