Hellabrunn Zoo is a 40 hectare zoological garden in the Bavarian capital of Munich. The zoo is situated on the right bank of the river Isar, in the southern part of Munich near the quarter of Thalkirchen. A high ratio of enclosures are cageless, relying upon moat features to keep the animals in place. The zoo was the first zoo in the world not organized by species, but also by geographical aspects. For example, the wood bison share their enclosure with prairie dogs.