his visit to the city around 1331, and commented favorably on the generosity, humility, and religion of its ruler, Sultan al-Hasan ibn Sulaiman. Ibn Battuta also describes how the sultan would go into the interior and raid the people taking slaves and other forms of wealth. He was also particularly impressed by the planning of the city and believed that it was the reason for Kilwa's success along the coast. From this period, the construction of the Palace of Husuni Kubwa and a significant extension to the Great Mosque of Kilwa, which was made of coral stones, the largest mosque of its kind. Kilwa was an important and wealthy city for the trade of gold. Because of trade, some of the people who lived in Kilwa had a higher standard of living, but many others were poor. The wealthy enjoyed indoor plumbing in their stone homes and the poor lived in mud huts with thatched roofs. In the early 16th century, Vasco da Gama extorted tribute from the wealthy Islamic state. In 1505 another Portuguese force commanded by D. Francisco de Almeida took control of the island after besieging it. It remained in Portuguese hands until 1512, when an Arab mercenary captured Kilwa after the Portuguese abandoned their outpost . The city regained some of its earlier prosperity, but in 1784 was conquered by the Omani rulers of Zanzibar. After the Omani conquest, the French built and manned a fort at the northern tip of the island, but the city itself was abandoned in the 1840s. It was later part of the colony of German East Africa from 1886 to 1918. Health & Education Since the resident island population is less than 1000 people, there is one school, The Lyahi Koranic Middle school. Older students move to the mainland for further education. There are no healthcare facilities on the Island so residents have to take the boat to the mainland to receive healthcare services at either the Masoka Urban Health Center ot the Masoko BAKWATA Dispensary both located in Kilwa Masoko town. See also Historic Swahili Settlements Swahili architecture References Further reading . Volume 1: History and archaeology; Volume 2: The finds. External links Kilwa Kisiwani Site Page from the Aluka Digital Library World Monuments Fund Project Page for Kilwa Free resource for tourists on Kilwa Description of the mosque at ArchNet, including pictures. Description of the palace at ArchNet;