Tanzania's oldest and most popular national park, the Serengeti National Park is also a World Heritage Site and one of the Seven Natural Wonders of the World, famed for its annual migration when some six million hooves pound the open plains - more than 2 million wildebeest accompanied by over 200,000 zebras and 300,000 Thomson's gazelles - in search of fresh green pastures. But even when the migration is quiet, the Serengeti still offers some of the best game viewing in Africa as it is home to a huge number of resident herbivores and predators who survey and protect their territories.