Who goes to the zoo in the middle of the night? I have no idea – it certainly isn’t me.
Freiburg’s Mundenhof is open 24/7 – though I would imagine a visit in the middle of the night might not be too satisfying of you want to see the animals. Most of them would probably be asleep. And the restaurant would be closed.
Mind you, seeing the animals properly isn’t guaranteed in the middle of the day either. On my visit last weekend it seemed like none of them wanted to cooperate.
Every time I came to a new enclosure the animals would turn and present their posteriors to me. Which didn’t make for the greatest pictures. Except for those enclosures with multiple angles – if I could move around they couldn’t stop me.