South Africa (officially the Republic of South Africa), is located on the southern tip of Africa. South Africa is the 25th-largest country in the world by land area and is the world's 25th-most populous nation. There are 11 official spoken languages in South Africa. There are two major airports: Cape Town International Airport and Tambo International Airport in Johannesburg. The diving in South Africa allows divers of all ability levels to explore truly spectacular scenery. A large number of most popular dive sites in South Africa are part of the Marine Protected Areas. The inland sites are used mostly for training, technical and cave diving. For those who prefer more secure and benign conditions, there are two large aquariums where divers can enjoy warmer water, easy access, and are guaranteed to see a large number of fish. One of the best places in the world to see Ragged Tooth sharks is Aliwal Shoal. This rocky reef is also visited by tiger sharks, brindle and potato bass as well as manta rays and dolphins. Another famous dive site is Santos Reef, which is home to stingrays, cuttlefish and a variety of local reef species. The region, known as one of the best places in South Africa to spot great white sharks, is Mossel Bay. This small harbor town in the heart of South Africa’s Garden Route has several dive sites that range from shallow (about 7m/23ft) to deep (30m/98ft). There divers have a chance to observe big fans, sponges, small reef fish, stingrays and rock cod. There are a lot of wrecks along the coast, some of which are regarded as great dive sites, for example: SAS Transvaal, SATS General Botha wreck, MFV Princess Elizabeth, MV Aster wreck and Coopers Light wreck. A large number of ships have been wrecked on South Africa's long, rugged and dangerous coastline during the last 500 years. Just about 2700 sunk, grounded, wrecked, abandoned or scuttled vessels found rest in South African waters.