The trading city of Kilwa, on the southern coast of Tanzania, has the largest group of pre-colonial ruins in East Africa! The former capital of the Kilwa Sultanate, Kilwa Kisiwani is a UNESCO World Heritage Site and you will need a permit to visit the island. Kivinje and Masoko, later settlements on the mainland, are a great base from which to visit Kilwa. The earliest settlements here date back to the eighth century, although few of these remains are still standing. A visit to the important ruins on nearby islands, including Songo Mnara, Sanje Majoma and Sanje ya Kate, is also quite enjoyable.