The Zanzibar Archipelago sits roughly 25 to 50 kilometres off the Tanzanian coast and comprises Unguja — the island most people mean by “Zanzibar” — along with Pemba to the north and a scatter of smaller islands.
Stone Town, the old quarter of Zanzibar City, has been a UNESCO World Heritage Site since 2000. Its coral-rag buildings, carved doors and narrow lanes record a thousand years of Swahili, Omani, Indian and European trade, including its role in the East African slave trade.
Beyond the town the draw is coastline and reef. The north around Nungwi and Kendwa has the most reliable swimming at all tides; the east coast is quieter and more tidal; Mnemba Atoll offers the archipelago’s best-known diving and snorkelling. Pemba, far less developed, has steep drop-offs that experienced divers rate above Unguja.