Second to the Lied Jungle I enjoyed visiting Primate Valley. Henry Doorly has a wonderful outdoor sloping enclosure for their gorillas. There is also an indoor viewing area for the primates.
Their orangutans were always indoors when I visited and I'm not sure if they have outside facilities for these beautiful creatures. As much as I admire Henry Doorly Zoo, there is more they could do for their orangutans.
The orangs were always more shy than the gorillas. I could stand for hours by the gorilla fence watching for the big silverback to run across the compound beating his chest. What a thrilling sight.
As Henry Doorly is always updaing and improving its exhibits, much of this may have changed since the last time I visited, which was in 1998.