So after looking at many photos of European zoos, I posit a hypothesis: that being, it seems relatively common for there to be public viewing for both indoor and outdoor enclosures for the majority of animals. While in the US this is largely true for apes (and perhaps also monkeys & elephants), it seems far less common; if animals choose, or are forced to be in their indoor enclosures, they are usually just off display to the public. I wanted people's input on whether this observation is true and if so, why that dichotomy exists.