Ilhéu das Rolas is a small island in São Tomé and Príncipe, in Africa. The island lies on the equator, off the southern tip of São Tomé Island. It is in the Caué District of São Tomé Province. The island is home to a small resort.The main and almost single economic activity is tourism related mainly to the resort. A permanent population of approximately 200 people works directly in tourism.Access to Rolas is exclusively by boat from Porto Alegre on the southernmost tip of São Tomé Island.
Gago Coutinho (1869–1959), officer of the Portuguese Navy, navigator and historian, headed a geodesic mission to São Tomé between 1915 and 1918 when marks were place as a basis for a geodetic network in the archipelago, and after that observations for triangulation, precise base measurement and astronomical observations were made.
In the process, Gago Coutinho proved that Ilhéu das Rolas is crossed by the equatorial line. The resulting map was delivered in 1919, together with the Report of the Geodetic Mission on São Tomé Island 1915–1918, that was officially considered the first complete work of practical geodesy in the Portuguese colonies.
