The Gibbon Cage (treated here was it it were an aviary because of its physical form) and the Cockatoo Aviary are similar structures. The Gibbon Cage has springy trapeze bars to provide the gibbons with the opportunity to exercise by arm swinging the length of the cage. When built this was the longest artificial gibbon run in the world. Built 1960-62, Franz Stengelhofen, architect. Pool bases landscaped 1981. Demolished in 2003.