The ancient city of Aden is located at the south west corner of Yemen. It was built at the base of a volcano that rises up to 300 metes from sea level. The old port was built in the back of the bay that was formed by the old volcano's crater. It is a natural bay protected from the wind and waves. It the ideal starting point for seas journeys. During the later part of the Roman Empire, Aden was an active port with shipping links to India, China and to Africa. Eritrea and Somalia could be reached in only a few days of sailing. The whole African East Coast, including the islands of Pemba, Zanzibar and Mafia had very early trade relations with the kingdom of Awsan through the harbor of Aden.
The unknown author ( probably 1st cent. AD ) of the "Periplus Maris Erythraei" gives a detailed description of the Red Sea Ports and part of the Arabian Coast east of Bab al - Mandab. He remarks on Aden: "Eudae mon Arabia ( Aden ), a settlement along the sea shore, belonging to the kingdom of Caribael ( Karib Il Wadi ), has favorable places for anchorage and fresh water supply. . . Freights are coming from India and Egypt: diamonds, sapphires, ivory, cotton, indigo. cardamom, pepper, dates, wine, myrrh, and frankincense"