Check out this photo I took in the "Rare Animal Conservation Center" at the Philly Zoo (not to be confused with the "International Conservation Center," which is the place outside Pittsburgh, equally artificial however).

http://www.helpphillyzooelephants.citymake...791/4964796.htm

The only greenery in the displays is the painted-on stuff on the cement walls. But what is really disturbing is the zookeeper hosing out the stalls while the lemurs are still in them. Is that messed up or what?