For me a visit to the local Zoo is a typical part of a city tour. At Hamburg the “Hagenbecks Tierpark” is conveniently reached by the public transportation.
Just after entering the park, at the elephant area a specially of the Zoo is immediately visible. People can feed the animals. This is of course a very special experience, especially with the elephants. They seem to be quite well adapted to that routine and line up at the border of their cage. Of course the animal trainers do see the scenery to keep the animals, and well also the people, a bit organized. The elephants do also accept coins, which they of course recognize immediately as non-food and pass them to the animal trainers as a small tip.
But the Zoo has more to offer than tip-accepting-elephants. Many of the other animal areas are constructed such that you have a plain view to the animals, without a fence or glass between. You can get an unobscured view such as on the orang utans as they play in their large place, which is quite jungle like.
Close to the real Zoo, there is also a tropical house (separate ticket required). So at the Zoo, there are hardly any reptiles, but mostly birds and mammals. The tropical house is then the place to see reptiles and fishes in all sorts. Also this place is build with a lot of fantasy and looks very nice. Just when you enter you are in the middle of an ape cage. Mostly you are being ignored by the inhabitants, but occasionally they use one of the visitors as a tree to climb up or jump from one side of the room to the other.