Totally agree .... there's been recent discussion about this in the Colchester threads and in another about changes you'd like to see at your local zoo.
The 2 indoor areas are linked by an overhead tunnel which can be closed at either end.
I've attached some thumbnails of the other areas, ostensibly called 'Feeding quarters' and 'Sleeping quarters', though they also often throw food onto the mesh ceiling of the larger 'living quarters' too (in the original photo).
The 2nd shows one of the sleeping areas - from which the chimps access the outside via a high level tunnel and the 3rd is the feeding quarters.