There are three distinct regions: the coastal plains (ranging between 20 and 300 km [10 and 190 mi] from the ocean’s shore), the mountains (the Cristal Mountains to the northeast of Libreville, the Chaillu Massif in the centre), and the savanna in the east. The coastal plains form a large section of the World Wildlife Fund’s Atlantic Equatorial coastal forests ecoregion and contain patches of Central African mangroves especially on the Muni River estuary on the border with Equatorial Guinea.
Gabon is notable for the Oklo reactor zones, the only known natural nuclear fission reactor on Earth which was active two billion years ago. The site was discovered during uranium mining in the 1970s to supply the French nuclear power industry.
Gabon’s largest river is the Ogooué which is 1,200 kilometres (750 mi) long. Gabon has three karst areas where there are hundreds of caves located in the dolomite and limestone rocks. Some of the caves include Grotte du Lastoursville, Grotte du Lebamba, Grotte du Bongolo, and Grotte du Kessipougou. Many caves have not been explored yet. A National Geographic Expedition visited the caves in the summer of 2008 to document them.
Gabon is also noted for efforts to preserve the natural environment. In 2002, President Omar Bongo Ondimba designated roughly 10% of the nation’s territory to be part of its national park system (with 13 parks in total), one of the largest proportions of nature parkland in the world. The National Agency for National Parks manages Gabon’s national park system.
Natural resources include petroleum, magnesium, iron, gold, uranium, and forests.
Gabon’s economy is dominated by oil. Oil revenues constitute roughly 46% of the government’s budget, 43% of the gross domestic product (GDP), and 81% of exports. Oil production is currently declining rapidly from its high point of 370,000 barrels per day in 1997. Some estimates suggest that Gabonese oil will be expended by 2025. In spite of the decreasing oil revenues, planning is only now beginning for an after-oil scenario. The Grondin Oil Field was discovered in 50 m (160 ft) water depths 40 km (25 mi) offshore, in 1971.
Gabonese public expenditures from the years of significant oil revenues were not spent efficiently. Overspending on the Trans-Gabon Railway, the CFA franc devaluation of 1994, and periods of low oil prices caused serious debt problems that still plague the country.
Gabon earned a poor reputation with the Paris Club and the International Monetary Fund (IMF) over the management of its debt and revenues. Successive IMF missions have criticized the government for overspending on off-budget items (in good years and bad), over-borrowing from the Central Bank, and slipping on the schedule for privatization and administrative reform. However, in September 2005 Gabon successfully concluded a 15-month Stand-By Arrangement with the IMF. Another 3-year Stand-By Arrangement with the IMF was approved in May 2007. Because of the financial crisis and social developments surrounding the death of President Omar Bongo and the elections, Gabon was unable to meet its economic goals under the Stand-By Arrangement in 2009. Negotiations with the IMF were ongoing.