Ngorongoro Crater is the world’s largest intact and unfilled volcanic caldera, and is indeed the flagship tourism attraction of the Ngorongoro Conservation Area. Measuring an area of 260 square kilometres and extending about 20km in diameter, the crater is actually a huge caldera of a volcano that collapsed to a depth of 610m about three million years ago. Over the course of time, streams of water made their way down the crater to form little ponds, and vegetation developed all over, attracting a wide range of wild animals. The crater is host to over 25,000 animals including populations of large mammals such as elephants, buffaloes, elands, wildebeests, zebras, gazelles, hippos, and rhinos, as well as such carnivores as lions, hyenas, jackals, and cheetahs. The ponds, or rather small lakes on the floor of the crater also host a wide-range of water birds including flamingoes and pelicans. Away from the crater floor, the forests on the crater rim is home to leopards, reedbuck, warthogs, and forest birds to complete a natural zoo, and Africa’s ultimate destination to see the “Big Five” (lion, elephant, rhino, leopard, and buffalo). Many animals stay in the crater large proportion of their lives, but others move out and may move back again. There are nine craters in the Conservation Area, of which Ngorongoro Crater is the biggest and most stunning. Before it collapsed, geologists estimate, its height was about 4,587m above sea level. The stunning landscape of Ngorongoro Crater combined with its spectacular concentration of wildlife is one of the greatest natural wonders of the planet. The crater was voted one of the Seven Natural Wonders of Africa in February, 2013, by the organization Seven Natural Wonders, based in the United States, which had conducted a campaign since 2008 to determine the most phenomenal natural features of Africa.