Libya is a North African country of about 1,759,540 km² on the Mediterranean coast, the fourth-largest in Africa, bordered by Egypt, Sudan, Chad, Niger, Algeria and Tunisia. Most of it is Sahara: rocky plateaus, sand seas and volcanic fields, with farmland confined to a coastal strip and two upland edges, the Nafusa Mountains in the west and the Jebel Akhdar in the east. The highest point is Bikku Bitti, 2,267 m, in the Tibesti Mountains on the Chad border; the lowest is the salt flat of Sabkhat Ghuzayyil, 47 m below sea level, just inland of the Gulf of Sidra. Libya has no permanent rivers at all, only wadis that flow after rain. Its fresh water comes overwhelmingly from fossil aquifers under the desert, piped north by the Great Man-Made River. Traditionally the country is split into three regions: Cyrenaica in the east (51 percent of the area), Fezzan in the south-west (33 percent) and Tripolitania in the north-west (16 percent). The descent below runs from the Tibesti summit to the lowest salt pan, region by region.
Bikku Bitti and the Tibesti, 2,267 Metres
Libya’s only true mountain range is the one it shares with Chad. The Tibesti Mountains rise in the central Sahara, mostly on the Chadian side, where the volcano Emi Koussi reaches 3,415 m, the highest point of the whole Sahara. Only the northern fringe crosses into Libya, and there, on a spur called Dohone, stands Bikku Bitti (also called Bette Peak), 2,266–2,267 m depending on the survey. It is so remote that the first known ascent came only in December 2005, when Ginge Fullen reached the summit on his third attempt.
The Tibesti owes its height to volcanism. A hotspot under the continent became active in the Oligocene and in places stayed active into the Holocene, piling lava plateaus on top of ancient Palaeozoic sandstone. Erosion then carved the plateaus into canyons, volcanic spires and gueltas, rock pools where the Toubou people water their herds. The name Tibesti is usually glossed as “place where the mountain people live”. On the Libyan side the range is almost uninhabited, and Libya’s borders with Chad and Niger run through some of the emptiest country on Earth.
The Haruj Lava Field and the Waw an Namus Crater
North of the Tibesti, the next high ground is also volcanic. The Haruj, in central Libya, is a field of dark lava spread over 42,000–45,000 km², roughly the area of Denmark. It holds about 150 volcanoes, mostly basaltic scoria cones plus about 30 small shield volcanoes, and its highest summit, Garet es Sebaa, stands about 1,200 m above sea level. Eruptions began roughly six million years ago, and the youngest lava flows may be only about 2,300 years old. As the lava spread it blocked ancient rivers, and the water backed up into a huge prehistoric lake that geologists call Lake Megafezzan.
South of the Haruj, on the old caravan route between Kufra and Sabha, lies Waw an Namus, a caldera ringed by a skirt of black tephra that stands out sharply against the pale desert around it. A young scoria cone rises inside the crater, and small lakes fringed with reeds lie at its foot. Their insects gave the place its name, which means “oasis of mosquitoes”. Its age is uncertain: radiometric dating gives about 200,000 years, but other evidence points to an eruption within the Holocene.
The Fezzan: Tadrart Acacus and the Ubari and Murzuq Sand Seas
West of the Haruj, the Fezzan drops into basins filled with sand. Two great ergs dominate it, each about 58,000 km². The Idehan Ubari takes its name from the oasis town of Ubari; idehan means “fine sand” in Tamasheq, the language of the Tuareg who have long herded here. Among its dunes, at the oasis of Gaberoun, lie the Mandara lakes, salty pools set among the dunes. Further south, the Idehan Murzuq is built of draa, giant sand ridges with smooth, almost sand-free basins between them. Smaller longitudinal, transverse and star dunes ride on their backs.
Along the Algerian border east of the town of Ghat, the Tadrart Acacus breaks out of the sand as a range of dark sandstone running about 100 km north from the frontier. Tadrart is the feminine Berber word for mountain. Its shelters hold thousands of rock paintings and carvings dated from about 12,000 BCE to 100 CE, made by hunter-gatherers and later herders; the oldest of them date from the African Humid Period, when the Fezzan held lakes and grassland. UNESCO listed the rock-art sites as a World Heritage Site in 1985.
The Nafusa Escarpment and the Jebel Akhdar
Descending northwards towards the coast, the land does not slope smoothly to the sea. Two limestone escarpments stand up near the Mediterranean, and both catch enough rain to support farming.
In Tripolitania, the Nafusa Mountains (Jabal Nafusa) are the broken northern edge of the Tripolitanian Plateau, reaching up to about 1,000 m. They face north over the coastal plain about 120 km inland. Deep gorges cut the scarp and made it easy to defend, and its Berber villages have grown olives and grain behind wadi walls since before Roman times. Springs along the scarp face are among the water sources best suited to future development.
In Cyrenaica, the Jebel Akhdar, the “Green Mountain”, is a plateau rising to about 900 m and fronting the coast for some 330 km from Benghazi to just beyond Derna. It was uplifted and arched into its present shape in the Miocene. It is the wettest place in Libya, with 400–600 mm of rain a year, and it carries about 3,200 km² of forest plus wide areas of maquis, with pine, juniper, cypress, wild olive and the endemic strawberry tree Arbutus pavarii. In one of the least-forested countries on Earth, that is enough to make it a landmark. Ancient Cyrene, one of Libya’s five UNESCO World Heritage Sites, was founded on its slopes.
The Calanshio Sand Sea and the Great Man-Made River
Behind the Jebel Akhdar, the land falls south into the Libyan Desert, the eastern Sahara that Libya shares with Egypt and Sudan. Its centrepiece is the Calanshio Sand Sea, about 62,000 km² of north–south dunes up to 110 m high, running some 500 km from the oases of Jaghbub and Jalo to Kufra. In 1943 the American bomber Lady Be Good ran out of fuel over it. Its crew bailed out believing they were still over the Mediterranean, when they were in fact more than 640 km inland. The wreck was found 15 years later, about 200 km north of Kufra.
Under this desert lies Libya’s real river. In 1953, oil prospectors drilling in the south found large reserves of fresh water in the Nubian Sandstone Aquifer System, rain that soaked in during wetter ages thousands of years ago. Work on the Great Man-Made River began in 1984; the first phase opened on 28 August 1991, and water reached Tripoli in 1996. According to the project, more than 1,300 wells, most deeper than 500 m, feed some 2,820 km of pipes and aqueducts. They carry about 6.5 million m³ a day up to 1,600 km north to Tripoli, Benghazi and Sirte, which is about 70 percent of the fresh water Libya uses. Because the aquifer is fossil water, it is barely recharged today.
Wadis of the Coastal Plains, from the Jifarah to Derna
At the foot of the escarpments lie the only lowlands with enough rain to farm without wells. Less than 2 percent of Libya gets enough rain for settled agriculture. In Tripolitania, the triangular Jifarah Plain covers about 15,000 km² between the Nafusa scarp and a coast of oases, lagoons and sand that runs for more than 300 km to the Tunisian border at Ras Ajdir. Tripoli, the capital and largest city of a country of about seven million people, sits on this plain. In Cyrenaica, the smaller Marj Plain forms a crescent about 210 km long between Benghazi and Derna and reaches at most 50 km inland.
With no permanent rivers, these plains rely on wadis, dry valleys that turn to torrents after heavy rain. They also rely on the dams built across them to store floodwater and check erosion. That system failed catastrophically in September 2023, when Storm Daniel, a Mediterranean tropical-like cyclone, dropped torrential rain on the Jebel Akhdar. Two dams on Wadi Derna, the Derna and Mansour dams, collapsed, and the flood tore through the city of Derna, killing more than 5,900 people, with thousands more missing.
The coast is also the hottest-reputed corner of Libya. A temperature reading at ʽAziziya on the Jifarah Plain on 13 September 1922 was long cited as the world record, until the World Meteorological Organization rejected it as unreliable in 2012.
Down to Sabkhat Ghuzayyil on the Gulf of Sidra
Between Tripolitania and Cyrenaica, the Sahara reaches the sea along the Gulf of Sidra, the ancient Syrtis Major. The gulf measures about 439 km across its mouth, reaches 177 km inland and covers some 57,000 km². Its shallows and sandbanks were feared by ancient sailors. On land, a barren zone called the Sirtica links the desert to the shore, and the gulf takes one of its names from the small oil port of Sidra.
Just south-east of the gulf, inland of Brega and near Ajdabiya, the ground sinks below sea level. Here lies Sabkhat Ghuzayyil, a salt flat 47 m below the sea and the lowest point in Libya. It is dry today, but during the wetter Holocene it held water. It is a fitting end point for a country whose water story is about absence: almost no rain, no rivers, and some 20 perennial lakes that are all brackish or salty.
For more on the desert that covers most of the country, see our guide to the Libyan Desert and the wider story of Sahara geography. The six countries around Libya, and the 4,348 km of land border it shares with them, are covered in the countries that border Libya.