Zanzibar is part of the East African republic of Tanzania. It consists of the Zanzibar Archipelago in the Indian Ocean, 25–50 km (15–30 mi) off the coast of the mainland. There are numerous small islands and two large ones: Unguja (the main island, informally referred to as "Zanzibar"), and Pemba. Zanzibar was once a separate state with a long trading history within the Arab world; it united with Tanganyika to form Tanzania in 1964, and still enjoys a high degree of autonomy within the union. The capital of Zanzibar, located on the island of Unguja, is Zanzibar City, and its old quarter, known as Stone Town, is a World Heritage Site.
Zanzibar's main industries are spices, raffia, and tourism. It is still sometimes referred to as the Spice Islands (a term also associated with the Maluku Islands in Indonesia), because of the significance of its production of cloves, of which it used to be the world leader, and also nutmeg, cinnamon and pepper. The ecology is of note for being the home of the endemic Zanzibar Red Colobus and the elusive Zanzibar Leopard.