One thing I have noticed about German enclosures is that many of them are very full of light , very "airy" & non-claustrophobic.More so than zoos in Mediterranean countries, which often incorporate enclosures that block out the light in an exaggerated fashion, which is a pity.Obviously shade is crucially important, but should be available as an option to the animal, rather than designing enclosures which admit very little light.Some Mediterranean zoo buildings are authentic bunkers, and I am not referring to nocturnal houses.
