It is impossible to say how many zoos are in the world. The World Association of Zoos and Aquariums (WAZA) has about 300 members, but the real number of the world’s zoos is minimum 15-20 times more. It is a little bit easier to find the oldest zoos, so let us see these. The oldest known zoological collection was revealed during excavations in Egypt, but it operated more than 3000 years ago. For simplicity, let us see the zoos which still exist and are open for visitors.