Port of Spain is the capital of an island.
Monte Trigo is the westernmost settlement on the island of Santo Antão and Cape Verde , also the whole of Africa together with the mainland and the islands . Port of Spain is the capital city of the Republic of Trinidad and Tobago and the country 's third-largest municipality , after Chaguanas and San Fernando . The city serves primarily as a retail and administrative centre and it has been the capital of the island since 1757 .