Cotonou is on the coastal strip between Lake Nokoué and the Atlantic Ocean. The city is cut in two by a canal, the lagoon of Cotonou, dug by the French in 1855. Three bridges are in this area. The Ouémé River flows into the Atlantic Ocean at Cotonou.

The name "Cotonou" means "by the river of death" in the Fon language. At the beginning of the 19th century, Cotonou (then spelled "Kutonou") was a small fishing village, and is thought to have been formally founded by King Ghezo of Dahomey in 1830. It grew as a centre for the slave trade, and later palm oil and cotton. In 1851 the French Second Republic made a treaty with King Ghezo that allowed them to establish a trading post at Cotonou. During the reign of King Glele (1858–89), the territory was ceded to the Second French Empire by a treaty signed in 1878. In 1883, the French Navy occupied the city to prevent British conquest of the area. After Glele's death in 1889, King Béhanzin unsuccessfully tried to challenge the treaty. The town grew rapidly following the building of the harbour in 1908.

When someday comes you'll need to get in.

When someday comes you'll need to be able to get around.