To make sure the Gray langurs won't escape, a total of 3 doors were placed on each exit. Two doors are made of wood and mesh and the other one is made of ropes.
The aviary used to hold birds and was built for their needs. The birds were moved out of the collection because they required different needs and they didn't fit in Apenheul's vision after all.
This year it was revamped to suit the needs of a small group of 1,2 Gray langurs. More will hopefully follow in the near future.