this was a very small cage but it joined up with the cage just visible to the left of the photo (which was even smaller) via the two wire tunnels that can be seen above the bushes. There is actually a patas monkey sitting in one of those tunnels in the photo. However the access to the larger cage appeared to be blocked off, effectively making the two cages separate, but I do not know if this is a permanent state of affairs or not.
August 2010. Review here:
http://www.zoochat.com/92/parc-zoologique-et-forestier-169406/