Tierpark Hagenbeck

Tucked away in Hamburg's northwestern suburb of Stellingen, Tierpark Hagenbeck, the city's zoo, was established in 1907 to house a collection of exotic animals owned by a local fishmonger-turned-exotic animal trader by the name of Carl Hagenbeck. The zoo is still run by his descendants.
This excellent facility was the first in the world to use open enclosures surrounded by ditches as opposed to cages, increasing the free-range area of the animals. It was also the first zoo to group animals by species, ideas that inspired the owners of other zoo parks to adopt.