On the Swahili Coast in southern Tanzania lie the ruins of a stone town known as Songo Mnara. The stone town was occupied from the 14th to 16th centuries. Songo Mnara has been recognized as a UNESCO World Heritage Site, along with nearby stone town Kilwa Kisiwani. In total, archaeologists have found six mosques, four cemeteries, and two dozen house blocks along with three enclosed open spaces on the island. Songo Mnara was constructed from rough-coral and mortar. This stonetown was built as one of many trade towns on the Indian Ocean.