of the East African Plateau. The southern half of this plateau is grassland within the Eastern miombo woodlands ecoregion, the majority of which is covered by the huge Selous National Park. Further north the plateau is arable land and includes the national capital, Dodoma. The eastern coast contains Tanzania's largest city and former capital, Dar es Salaam. Just north of this city lies the Zanzibar Archipelago, a semi-autonomous territory of Tanzania which is famous for its spices. The coast is home to areas of East African mangroves, mangrove swamps that are an important habitat for wildlife on land and in the water. A recent global remote sensing analysis suggested that there were 1,256km² of tidal flats in Tanzania, making it the 26th ranked country in terms of tidal flat area. Watersheds Eastern and central Tanzania are drained by rivers that empty into the Indian Ocean. The major rivers are, from north to south, the Pangani, Wami, Ruvu, Rufiji, Matandu, Mbwemkuru, and the Ruvuma River, which forms the southern border with Mozambique. Most of Northern Tanzania drains into Lake Victoria, which empties into the Nile River. The western portion of Tanzania is in the watershed of Lake Tanganyika, which drains into the Congo River. The Malagarasi River is the largest tributary of Lake Tanganyika. Part of southwestern Tanzania drains into Lake Malawi, which empties south into the Zambezi River. The Southern Eastern Rift area of north-central Tanzania is made up of several endorheic basins, which have no outlet to the sea and drain into salt and/or alkaline lakes. Lake Rukwa in west-central Tanzania, is another endorheic basin. Climate Tanzania has a mainly tropical climate but has regional variations due to topography. In the highlands, temperatures range between during cold and hot seasons respectively and a subtropical highland climate is found. The rest of the country has temperatures rarely falling lower than . The hottest period extends between November and February () while the coldest period occurs between May and August (). Seasonal rainfall is driven mainly by the migration of the Intertropical Convergence Zone. It migrates southwards through Tanzania in October to December, reaching the south of the country in January and February, and returning northwards in March, April, and May. This causes the north and east of Tanzania to experience two distinct wet periods – the short rains (or "Vuli") in October to December and the long rains (or "Masika")