The enclosures immediately in front and to the left are for the orangs and langurs. The one just visible to the right, beyond the concrete viewing structure, is for Smooth-coated Otters.
As I understand it, there are 4 indoor enclosures and 3 outdoor enclosures for the orangutans. The animals can use all areas for most of the time. The nets between the enclosures provide additional climbing opportunities. Furthermore, the circular shape of the building is meant to represent the dense rainforest, which presumably gives the animals a greater sense of security. The concrete tunnels in the background are the paths between the enclosures, which could not be altered during construction due to heritage protection regulations.
@RonBurrgundy is correct. Although it is worth adding that on the other side of the concrete tunnel is not an additional orangutan enclosure, but rather the outdoor Smooth-coated Otter enclosure. I personally love the o-shaped building and the idea of having enclosures in the centre. If I am not mistaken, the social structure of orangutans is notoriously difficult for zoos to work with, so having a multitude of enclosures (no less than seven) is of huge benefit.
