Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and the Indian Ocean to the east; Mozambique and Malawi to the south; Zambia to the southwest; and Rwanda, Burundi, and the Democratic Republic of the Congo to the west. Mount Kilimanjaro, Africa's highest mountain, is in northeastern Tanzania. According to the United Nations, Tanzania has a population of 63.59 million, making it the most populous country located entirely south of the equator. Tanzania's population is composed of about 120 ethnic, linguistic, and religious groups. The sovereign state of Tanzania is a presidential constitutional republic and since 1996 its official capital city has been Dodoma where the president's office, the National Assembly, and all government ministries are located. Dar es Salaam, the former capital, retains most government offices and is the country's largest city, principal port, and leading commercial centre. Tanzania is a de facto one-party state with the democratic socialist Chama Cha Mapinduzi party in power. Tanzania is mountainous and densely forested in the north-east, where Mount Kilimanjaro is located. Three of Africa's Great Lakes are partly within Tanzania. To the north and west lie Lake Victoria, Africa's largest lake, and Lake Tanganyika, the continent's deepest lake, known for its unique species of fish. To the south lies Lake Malawi. The eastern shore is hot and humid, with the Zanzibar Archipelago just offshore. The Menai Bay Conservation Area is Zanzibar's largest marine protected area. The Kalambo Falls, located on the Kalambo River at the Zambian border, is the second-highest uninterrupted waterfall in Africa. Christianity is the largest religion in Tanzania, but there are also substantial Muslim and animist minorities. Over 100 different languages are spoken in Tanzania.