Lagos is built on the mainland and the series of islands surrounding Lagos Lagoon. Originally a small village, known as Eko, its position as one of the few natural harbours on the Atlantic coast made it a principal site for European contact. From the fifteenth century, sailors from Portugal established a trading post on the island, which they renamed Lagos, after a town in southern Portugal. Trade was in spices, ivory and slaves. The town was taken over by the British in 1807 in an effort to stamp out the slave trade. Lagos was incorporated into the colony of Nigeria in 1900.
The main commercial and administrative centre of Lagos remains Lagos Island, which is connected to the mainland by three large bridges. Ikoyi and Victoria islands are closely connected to Lagos Island. The main docks are in Apapa directly opposite Lagos Island. Other districts on the mainland include Ebute-Meta, Surulere, Yaba (site of Lagos University), Mushin, and Ikeja, site of the International Airport.
Transport links within Lagos are congested, due both to the geography of the city, and its explosive population growth. A chain of salt-water lagoons runs west to Badagri and also east toward the Niger delta.