This ancient isle once ruled by sultans and slave traders served as the stepping stone into the African continent for missionaries and explorers. Today it attracts visitors intent on discovering sandy beaches, pristine rain forests, or colorful coral reefs. Once known as the Spice Island for its export of cloves, Zanzibar has become one of the most exotic flavors in travel, better than Bali or Mali when it comes to beauty that’ll make your jaw drop.Separated from the mainland by a channel only 35 km (22 miles) wide, and only 6 degrees south of the equator, this tiny archipelago—the name Zanzibar also includes the islands of Unguja (the main island) and Pemba—in the Indian Ocean was the launching base for a romantic era of expeditions into Africa. Sir Richard Burton and John Hanning Speke used it as their base when searching for the source of the Nile. It was in Zanzibar where journalist Henry Morton Stanley, perched in an upstairs room overlooking the Stone Town harbor, began his search for David Livingstone.The first ships to enter the archipelago's harbors are believed to have sailed in around 600 BC. Since then, every great navy in the Eastern Hemisphere has dropped anchor here at one time or another. But it was Arab traders who left an indelible mark. Minarets punctuate the skyline of Stone Town, where more than 90% of the residents are Muslim. In the harbor you'll see dhows, the Arabian boats with triangular sails. Islamic women covered by black boubou veils scurry down alleyways so narrow their outstretched arms could touch buildings on both sides. Stone Town received its odd name because most of its buildings were made of limestone and coral, which means exposure to salty air has eroded many foundations.The first Europeans who arrived here were the Portuguese in the 15th century, and thus began a reign of exploitation. As far inland as Lake Tanganyika, slave traders captured the residents or bartered for them from their own chiefs, then forced the newly enslaved to march toward the Indian Ocean carrying loads of ivory tusks. Once at the shore they were shackled together while waiting for dhows to collect them at Bagamoyo, a place whose name means, "here I leave my heart." Although it's estimated that 50,000 slaves passed through the Zanzibar slave market each year during the 19th century, many more died en route.Tanganyika and Zanzibar merged in 1964 to create Tanzania, but the honeymoon was brief. Zanzibar's relationship with the mainland remains uncertain as calls for independence continue. "Bismillah, will you let him go," a lyric from Queen's "Bohemian Rhapsody," has become a rebel chant for Zanzibar to break from Tanzania.Zanzibar Island, locally known as Unguja, has amazing beaches and resorts, decent dive spots, acres of spice plantations, the Jozani Forest Reserve, and Stone Town. Plus, it takes little more than an hour to fly there. It's a popular spot to head post-safari.Stone Town, the archipelago's major metropolis, is a maze of narrow streets lined with houses featuring magnificently carved doors studded with brass. There are 51 mosques, 6 Hindu temples, and 2 Christian churches. And though it can rightly be called a city, much of the western part of the larger island is a slumbering paradise where cloves, as well as rice and coconuts, still grow.Although the main island of Unguja feels untouched by the rest of the world, the nearby islands of Pemba and Mnemba offer retreats that are even more remote. For many years Arabs referred to Pemba as Al Khudra, or the Green Island, and indeed it still is, with forests of king palms, mangos, and banana trees. The 65-km-long (40-mile-long) island is less famous than Unguja except among scuba divers, who enjoy the coral gardens with colorful sponges and huge fans. Archaeology buffs are also discovering Pemba, where sites from the 9th to the 15th century have been unearthed. At Mtambwe Mkuu coins bearing the heads of sultans were discovered. Ruins along the coast include ancient mosques and tombs. In the 1930s Pemba was famous for its sorcerers, attracting disciples of the black arts from as far away as Haiti. Witchcraft is still practiced, and, oddly, so is bullfighting. Introduced by the Portuguese in the 17th century, the sport has been improved by locals, who rewrote the ending. After enduring the ritual teasing by the matador's cape, the bull is draped with flowers and paraded around the village.Beyond Pemba, smaller islands in the Zanzibar Archipelago range from mere sandbanks to Changu, once a prison island and now home to the giant Aldabra tortoise, Chumbe Island, and Mnemba, a private retreat for guests who pay hundreds of dollars per day to get away from it all.