Gabon is a country in west-central Africa bordering the Atlantic Ocean and Gulf of Guinea at the Equator. It shares borders with Equatorial Guinea to the northwest, with Cameroon to the north and with the Republic of the Congo to the east and south. Gabon covers a total area of 267,667 km2 of which about 3.7% is water. The terrain comprises a narrow coastal plain with patches of mangroves and a hilly interior comprising the Cristal Mountains in the northeast and Chaillu Massif in the centre risiing to 1575m at Mont Iboundji. Gabon has three major karst areas where there are hundreds of caves. It’s largest river is the Ogooué which is 1200km long. Rainforest covers about 85% of the country and is the highest proportion in Africa. More than 11% of the nation's territory is national park, one of the highest percentages of any nation the world.


Gabon is located at the north-western margin of the Congo Craton. Three major stratigraphic units can be distinguished: Archean basement and Proterozoic supercrustals, which together cover about 75% of the country, and the Phanerozoic sedimentary cover, which is dominantly of Cretaceous age or younger. The oldest units belong to the cratonic basement of West Africa and comprise a granitoid terrane in the south, the Chaillu Massif, and a mixed granitoid-granulite-charnockite assemblage in the north. Proterozoic rocks comprise meta-sedimentary and volcanic of variable grade and a series of high-grade remobilised basement domes plus a major suite of dolerite dykes dated at 970Ma.