@Cat-Man: I agree with your response! There's nothing quite like seeing apes on concrete islands. It actually seems that there are a couple of potted plants for the gibbons to stare at...
This exhibit was build at the end of the 50ty years,altough it is not good looking, its better than much newer gibbon exhibits. And Gibbons don'tc are about a concrete floor of their exhibit, they are most of the time in the trees. I would say, hell is not looking that way. So I would say, go to asia or to arbian countries and see, how gibbons and other animals are being kept in zoos there.. This old exhibit will be destroyed in the next years, the pond will be used for the hippos.