I think zoo biology has five milestones. The first is, was achieved with the opening of Hagenbeck’s Tierpark in Hamburg. Hagenbeck’s animal park in Hamburg. Hagenbeck has had a circus and trains lions and tigers to reach the distance they can jump. And afterwards, he built his animal park, by the way, it was planned by Hagenbeck but actually built by a Swiss sculptress, Vors Eickenweiler. And from this circus training, he knew how far the lions can jump. There are several tricks that the visitor side is a bit higher than the animal side and so on. But for the first time, visitors could see carnivores without fences.
