Zanzibar is an archipelago consisting of the main island Zanzibar, its sister island Pemba in the north and several smaller islets. It is an autonomous part of the United Republic of Tanzania. The main island, which in Swahili is called Unguja, reaches from the village Nungwi in the north to Stone Town, the world famous Old Town of Zanzibar City. The area of Unguja is about 1658 square km. Besides Stone Town, the island is known for its cultural and biological diversity. On the east-coast you can find beautiful white sandy beaches and offshore coral reefs. Tourism is an important economic sector of the island. Pemba, the Green Island, has an area of 984 square km. It is largely untouched and always green because infrastructure and tourism are barely nonexistent. Therefore Pemba is very popular with divers. There is a ferry service from the island’s capital Chake Chake to Zanzibar and a small number of local flights. Some islets like Chumbe and Chapwani provide comfortable accommodation for the visitors. Other islets like Prison Island or Snake Island are only advisable for day trips.