When it comes to impressive historic zoos, it’s hard to beat the Zoologischer Garten of Berlin. Translating as the Berlin Zoological Garden, this zoo was opened in 1844 and is a great source of pride for Berlin locals. But Berlin Zoo isn’t just a heritage site, it’s also the world’s biggest zoo when measured by number of animals. There are a whopping 20,200 animals across 1,380 different species here at this city zoo, which also makes it a key player in many different breeding programs. On its 86 acres you can discover a dizzying variety of animals which includes polar bears, giant pandas, lemurs, and many other kinds of primates.