Zanzibar was an important island in the Swahili Coast trading network of cities in Africa. Its oldest Stone Town center dates from the period when Persian traders used it as a base for trade with the Middle East and Asia. Its products, spices such as cloves, nutmeg, cinnamon and pepper, combined with the cultivation of the perfume essence ylang ylang, remain important today. The Stone Town is a UNESCO World Heritage Site, inscribed because of its unique hybrid culture influenced by the Arab, Persian, African and Indian peoples who traded across the Indian Ocean following the seasonal monsoon routes. Important architectural features include the Old Fort, the 18th century House of Wonders, the house where Dr. Livingstone lived, the Old Dispensary of Zanzibar and the Hamamni Persian Baths built in the 18th century in the town of Kidishi.