I hope these Wombats don't have 'researchers' hanging about all day long to prevent them from digging and doing other natural behavior, as at the Australia Zoo, remember our earlier talk. This looks fake but I really think it is just the indoor den. I'm fairly sure I remember a nice outdoor exhibit but maybe Sim, Pat or someone else from Melbourne can confirm please.
The wombats have a few different exhibits both on show and off show but seeing as they are a mostly nocturnal species they also have burrows on show. To view these burrows that visitors need to enter a giant underground burrow themselves. The burrow area is very dark but you can't really tell in this photo. It is a very popular area and there are two or so groups on display so you're pretty much garunteed to see wombats.