The island of Zanzibar, once the metropolis of East Africa, variously ruled by Shirazi Persians, the Portuguese, the Omani Arabs and British colonials, is only 20 minutes' flight from Dar es Salaam (ferries are also available). Otherwise known as the 'Spice Island', Zanzibar's golden age was under the Omani Arabs in the early 19th century. By the middle of the century, it had become the world's largest producer of cloves and the largest slave-trading post on the African eastern coast. Zanzibar's old Stone Town, a UNESCO World Heritage Site, is a labyrinth of narrow, winding streets lined with exotic shops, bazaars, colonial mansions, mosques and squares. The visitor can still see the house where Dr Livingstone lived, as well as that used by Burton and Speke. The Anglican Cathedral Church of Christ stands on the site of the Old Slave Market, off Creek Road, while on the seafront are the palace of the former sultan and the towering Beit-el-Ajaib (The House of Wonders). Zanzibar is a fascinating place with palaces, forts, stone aqueducts and baths; its history as a cosmopolitan center of trade gives it a unique atmosphere. The guided Spice Tours are recommended (see also Top Things To Do). Within the vicinity lie many offshore islands ringed with coral reefs, the most famous and most visited being Changuu Island (also known as 'Prison Island'). There are also many superb beaches, particularly on the east coast, although there are now several package hotels there.