The equator marked as it crosses São Tomé and Príncipe. Credit

São Tomé and Príncipe is an island nation in the Gulf of Guinea, off the western equatorial coast of Africa. It consists of two islands: São Tomé and Príncipe, located about 140 kilometres apart and about 250 and 225 kilometres respectively, off of the northwestern coast of Gabon. Both islands are part of an extinct volcanic mountain range. São Tomé, the sizable southern island, is situated almost exactly on the equator. It is named after Saint Thomas by Portuguese explorers who discovered the island on his feast day.

São Tomé and Príncipe is the second smallest (in terms of population) African country (larger only than Seychelles). It is the smallest country in the world that is not a former US trusteeship, a former UK dependency, or a European microstate. It is also the smallest Portuguese-speaking country in the world.