Has anyone every seen a truly innovative giant snake exhibit? Something that goes beyond the normally sterile but for a concrete pond and a concrete tree?
Singapore Zoo had a walk through snake exhibit with small reticulated pythons, not I expect what you were talking about. I remember seeing it when I went through about 20 years ago, but on my last visit last year it was empty and looked unused for some time.
The anaconda exhibit at San Antonio Zoo is pretty neat. Big water area with some partially submerged branches, so you can see the snake chillin' on the branch partially in and out of water. Also has some plants, dirt, nice rocks, makes it look real natural.
The python exhibit in Jungleworld at the Bronx Zoo was considered to be one of the zeniths of naturalistic zoo design. It was positioned above the visitor's walkway and angles such that it looked like the python was out in the open.
Not sure all that innovative but the reptile park next to the bird park in Bali has a great large enclosure for boa constrictors with glass wall and the enclosure is built in a L shape against what looks like the steps to a temple with underwater viewing also available.
Many zoos in Europe have natural substrate and real branches. Live plants don't hold very well with heavy snakes. Pythons in Berlin zoo are somehow always impressively stretched. I think there is a heating cable buried underground so the snake shows itself. A few zoos have walk-through rooms with boa constrictors. If I was to design such exhibits, for green anacondas I would make a shallow pool with floating water hiacynth, seen from the little bridge above. For pythons I would make mock tangle of strangler fig branches with glass window inside, looking to the rest of exhibit away. Pythons are nocturnal and spend the daytime hidden in dark places.
Prehistoric pets/The reptile zoo in Anaheim, California had a great enclosure for twinkie, the huge albino reticulated python, she unfortunately passed away this year, but the enclosure is still being used for another large retic. large snakes don't really lend themselves to being great display animals, because they don't move around all that much, and prefer to coil up hidden away from view all day, a good exhibit might be to have a large anaconda in an aquatic set-up where the water level extends part way up the viewing glass, enabling the visitor to see the snake underwater at it's level instead of just looking into a pool from above, I think it is the west midlands safari park that has a good anaconda enclosure like this. alligator bay in france also had some good large constrictor enclosures when i was there last.