It is an attraction on Ventureland reintroduced in Epic Mickey 2, where you will need to pass it in order to find the area where Gremlin Prescott had been working to find some clues. There are multiple ways to enter it, two are related to a quest. The other is by climbing the treehouses and entering the long one.
In it the elephants from the real attraction its vehicles are in it. After that you'll need to pass Pete Pan to get to the next area.