West Africa in the map from Wikipedia.
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries distributed over an area of approximately 5 million square km:
With the exception of Mauritania, all of these countries are members of the ECOWAS or Economic Community of West African States. The UN region also includes the island of Saint Helena, a British overseas territory in the South Atlantic Ocean.