I visited what I think was this house many years ago. Then it was horribly sterile. They've obviously made it more 'friendly' now with mulch flooring etc but I think the cages are the same ones. There was a large collection of Monkeys as well as the Apes.
I was there previously in 1999 and then I think it was as sterilised as many other primate houses in Germany, but I was pleasantly surprise on my return visit in 2004. Sadly I have not been back since, but Duisburg remains one of my top 5 German zoos.
My guess would be the mid-1970s but the German members will be able to give you the exact year. However, what you see here is an early 2000s most successful renovation. I visited before in 1999 and recall it as just as bare as many primate buildings in Germany are still.
The Äquatorium was opened in 1962. At this time, it was the biggest primate house in the world. Not only the house was big, also the collection of primate species was unbelivable huge.
@Pertinax
The cages are the same, but they look more friendly now (fake rocks).
The mandrills left te house recently and are living at the polar bear enclosure now, so there is more space now for Macaca silenus, guenons and gibbons now.
