Zanzibar is a semi-autonomous part of Tanzania, in East Africa. It is composed of the Zanzibar Archipelago in the Indian Ocean, 25–50 kilometres (16–31 mi) off the coast of the mainland, and consists of numerous
small islands and two large ones: Unguja (the main island, referred to informally as Zanzibar), and Pemba.
The capital of Zanzibar, located on the island of Unguja, is Zanzibar City. Its historic centre, known
as Stone Town, is a World Heritage Site and is claimed to be the only functioning ancient town in East Africa.