Wow...a ton of poles/sticks poking up into the air!! Seriously though, it probably allows for the gibbons to brachiate with ease. An exhibit that appears to be custom-built for its inhabitants.
It certainly isn't "new"-this was built in the 1970s/early 1980s and part of it is also inhabited by Black-headed Spider Monkeys. The interior exhibit was slightly redone a few years ago.