(I've recently located a box of 35mm photograhic slides that I'd mislaid; this box contains a number of my photos from European zoo visits in the late 1980s and early 1990s.
I've had some of these pictures digitally scanned for uploading to ZooChat. More will follow in due course.)
Growing up I used to regularly see them in Jungle World at my home zoo (Bronx) not really grasping how special that was.
Currently I know only of zoos located in Asia: Singapore Zoo, Taman Safari Bogor, Taman Safari II- Prigen, Labuk Bay Proboscis Monkey Sanctuary, Lok Kawi Wildlife Park, and Zoorasia. The first two of which I was lucky enough to visit last year!
Oops thanks @Chlidonias! Had seen Chimelong in zoochat photos but forgot to list it. Didn't know about Surabaya!
According to zootierliste there are none left in Europe. Apenheul in Netherlands was most recent to house them from 2011-2015 sending their last remaining male to Singapore.