@Pertinax
The gorilla indoor area at Wuppertal is a little bit bigger than the area at the old Great Ape House at Frankfurt, but not better than the old one (~115m² vs. 93m²)
All the same in german zoos, great looking and big outdoor exhibits for the big apes, but indoors,which is much more important, because the animals are spend most of their lifes indoors, small and boring. Fortunately, Frankfurt ( excellent indoor exhibits now ) and Leipzig ( nice, but not perfect indoor exhibits ) have shown its possible to do it much better.
@Charly
The Orang-Utan indoor exhibit at Frankfurt is excellent, the gorilla indoor exhibit is not better than the one at Leipzig, the bonobos exhibit at Leipzig is the best one I have ever seen.
All the same in german zoos, great looking and big outdoor exhibits for the big apes, but indoors,which is much more important, because the animals are spend most of their lifes indoors, small and boring.
I think historically this has always related to cost- indoor areas require superstructures/building materials/ construction/labour etc etc so often are confined in to the smallest acceptable size to keep those costs down. Outdoor areas are cheaper to construct- a wall or moat around a large open area is a far less labour intensive construction. It is the wrong balance as you said- and often the outdoor areas remain little or under used. Some Zoos nowadays are finally realising this but I still see many where the ratio indoors/outdoors is entirely wrong- others I know of like this are Apenheul, London, Jersey and Bristol Zoos to name just a few.
