The island and the surrounding islets are divided into three regions. They are Zanzibar Central/South, Zanzibar North and Zanzibar Urban/West. Zanzibar City, on the central west coast, is the capital and largest city of Zanzibar and the region of Zanzibar Urban/West. The population of Unguja was 984,625 in the census of 2002, with the most concentrated populations located in the Zanzibar Urban region.
The larger and more populated of Zanzibar's two main islands, Unguja is separated from its northern neighbour Pemba by some 48i kilometres of open sea. The mainland of Tanzania, which lies to the southwest of Unguja and is separate from it by the Zanzibar Channel, is considerably closer, as is the major Tanzanian mainland port of Dar Es Salaam. Smaller islands surround the coast, notably Tumbatu in the northwest, Uzi in the south, and Mnemba Atoll in the northeast. A considerable number of smaller islands and reefs lie off Unguja's southwest coast.
Many of Zanzibar's main centres are on Unguja, and most of the Zanzibari economy is also based here. Other than the capital, the island's major population centres include Mbweni, Mangapwani, Chwaka, and Nungwi. Tourism is a major industry.
The island is rich in history, with numerous archaeological sites dotting the island, most notably at Unguja Ukuu, just to the north of the causeway which links Unguja and Uzi Islands.