The boardwalk goes around 2 large orangutan exhibits (2.3 of the apes live here) and the tall trees are perfectly fine for the red apes to climb on. I've seen orangs as high as the boardwalk as they clamber up the trees, and that is a major reason why I think that this is the best exhibit of its kind in North America. The indoor areas are viewed entirely through glass, and there are also some glass viewing windows outdoors. So essentially the treetops area, the land area, and the indoor area all have ample viewing locations for the public. Just before these enclosures are exhibits for siamangs and lion-tailed macaques which are also brilliant.