The islands of São Tomé and Príncipe are located in the Atlantic Ocean, in the Gulf of Guinea, approximately 300 km from the western coast of Africa. With two main islands and more than ten islets and rocks, the Archipelago extends over an area of 1001 km², formed by volcanic eruptions on underwater platforms. The largest island, São Tomé, has an area of 859 km² and is 65 km long and 35 km wide. Príncipe has an area of 142 km² and is 16 km long and 8 km wide. The distance between the two islands is around 140 km and Príncipe is situated to the northeast of São Tomé. 

The Archipelago offers stunning and majestic landscapes with the exuberant tropical vegetation that is its signature, creating a scenery of rare beauty. The landscape is very mountainous, with altitudes exceeding one thousand metres. The highest point in the Archipelago, Pico de São Tomé, rises to 2024 m and other peaks include Calvário, Cabumbé, Cão Grande and Pico do Príncipe. 

The islands of São Tomé and Príncipe are known as The Islands in the Middle of the World, since they lie on the Equator, very close to the Greenwich Meridian. The Gulf of Guinea is where the Equator (0º latitude) and the Greenwich meridian (0º longitude) meet.