sentences:  One of the oldest harbours documented in Southern Africa, medieval Sofala was erected on the edge of a wide estuary formed by the Buzi River (called "Rio de Sofala" in older maps).By the Somali merchants from Mogadishu, the capital of the Ajuran Empire, established a colony in Mozambique to extract gold from the mines in Sofala.The Buzi River connected Sofala to the internal market town of Manica, and from there to the gold fields of Great Zimbabwe.