Lebanon occupies 10,452 square kilometers on the eastern Mediterranean coast, a territory smaller than Connecticut but containing four distinct parallel zones running north to south. The narrow coastal plain averages 6 kilometers wide, broadening only at Akkar in the north and near Sidon in the south. Behind this rises the Mount Lebanon range, a limestone massif reaching 3,088 meters at Qornet es Saouda, the country's highest point. The Beqaa Valley, a northern extension of Africa's Great Rift Valley, separates Mount Lebanon from the Anti-Lebanon Mountains, which form the Syrian border and culminate at 2,814 meters at Mount Hermon's Lebanese slopes. This compressed topography produces the region's most extreme elevation change over short distance: a traveler can stand at sea level in Beirut and see snow-capped peaks 50 kilometers inland on the same winter day.
The Mediterranean coastline extends 225 kilometers from Naqoura at the southern border with Israel to Arida at the northern border with Syria. Rocky headlands alternate with small sandy beaches, though centuries of unregulated construction have eliminated public access along much of the Beirut metropolitan area. Pigeon Rocks at Raouché, two natural limestone arches rising 70 meters from the sea just west of Beirut, mark the capital's most photographed coastal feature. The Palm Islands Reserve, three small islands 5.5 kilometers northwest of Tripoli, became Lebanon's first marine protected area in 1992, covering 4.2 square kilometers of critical Mediterranean monk seal habitat, though no confirmed sightings have occurred since 2010. North of Beirut, the coastline becomes increasingly dramatic, with cliffs dropping directly to the water near Batroun and Chekka.
Mount Lebanon consists primarily of Jurassic and Cretaceous limestone laid down when this region sat beneath the Tethys Sea 150 million years ago. Erosion carved this porous rock into extensive cave systems, with over 400 documented caves though only a fraction explored. Jeita Grotto, 18 kilometers northeast of Beirut, contains two separate limestone galleries totaling 9 kilometers in surveyed length, though the full extent remains unmapped. The lower grotto carries an underground river navigable by boat for 500 meters, its water eventually joining the Nahr el-Kalb River. Qammouaa Grotto near Batroun descends through multiple chambers to a depth of 255 meters, making it the deepest explored cave in the Middle East. These karst formations create Lebanon's defining hydrological characteristic: most precipitation percolates directly through limestone rather than forming surface streams, emerging in powerful springs at valley floors.
The Litani River, Lebanon's longest watercourse at 140 kilometers, rises near Baalbek in the northern Beqaa Valley and flows southward parallel to the Israeli border before turning sharply west to cut through Mount Lebanon at Qaraoun. The river's total drainage basin covers approximately 2,000 square kilometers, nearly one-fifth of Lebanon's territory. The Qaraoun Dam, completed in 1959, created Lebanon's largest reservoir at 220 million cubic meters, though siltation has reduced capacity by an estimated 35 percent. The Litani's unusual course—flowing away from the sea before turning—reflects its capture by headward erosion through Mount Lebanon, a geologically recent event that separated its upper valley from what likely formed a continuous drainage system extending into modern Syria. Other significant rivers include the 31-kilometer Nahr el-Asi (Orontes) in the far north, which enters Lebanon from Syria, and the Nahr el-Kalb, whose 31-kilometer course from Mount Lebanon to the Mediterranean features dramatic gorges where at least 22 conquering armies carved commemorative inscriptions from Egyptian pharaohs to French forces.
The Beqaa Valley extends approximately 120 kilometers north-northeast from the Rashaya district to Hermel, averaging 16 kilometers wide between the mountain ranges. At 900 meters elevation, this high plateau receives less rainfall than coastal areas but benefits from snowmelt flowing from both mountain ranges. The watershed divide occurs near Baalbek: north of this point, water flows to the Orontes River and eventually the Mediterranean via Turkey; south of it, water feeds the Litani. Intensive agriculture covers the valley floor, with approximately 40 percent of Lebanon's arable land concentrated here despite the valley representing only 11 percent of national territory. The Ammiq Wetland, 7 square kilometers of marsh remnant in the central Beqaa, constitutes Lebanon's last significant natural wetland, its size reduced from an estimated 70 square kilometers in the 1930s by drainage for agriculture.
Lebanon's climate transitions sharply with elevation. The coastal strip experiences hot-summer Mediterranean conditions with average July temperatures reaching 28 degrees Celsius in Beirut and winter minimums rarely falling below 10 degrees. Annual rainfall at sea level averages 860 millimeters in Beirut, concentrated between November and March. The western slopes of Mount Lebanon capture orographic precipitation, with stations above 1,500 meters recording over 1,400 millimeters annually. Above 2,000 meters, snow covers the ground from December through April, with the Cedars of God near Bcharre typically maintaining snowpack from late November to early May. The Beqaa Valley sits in a rain shadow, receiving 600 millimeters in Zahle and as little as 230 millimeters in the northern extremes near Hermel. This climatic compression produces agricultural zones more characteristic of countries spanning 20 degrees of latitude: citrus and bananas grow at sea level while apple orchards thrive at 1,200 meters and potatoes grow at 1,800 meters.
The Cedars of God, known in Arabic as Horsh Arz el-Rab, covers 102 hectares on the western slopes of Mount Lebanon at 2,000 meters elevation near Bcharre. This grove contains approximately 375 individual cedars of God—Cedrus libani—including several specimens exceeding 1,200 years old based on dendrochronological analysis. The largest measured tree, the "Sisters" cedar, shows a trunk circumference of 14 meters, though whether this represents a single individual or fused multiple trunks remains debated. These remnants represent a tiny fraction of extensive cedar forests that once covered an estimated 500,000 hectares of Lebanese mountains. Phoenician timber trade, documented in Egyptian papyri from 2600 BCE, Egyptian temple inscriptions describing cedar imports for shipbuilding and construction, and the Epic of Gilgamesh's description of cedar cutting all reference these forests. Ottoman demand for railroad ties in the 19th century accelerated deforestation already advanced by centuries of shipbuilding, construction, and charcoal production. Natural regeneration above 1,400 meters continues slowly, inhibited by goat browsing and competition from Cilician fir and other species expanding upslope as climate warms.
The Chouf Cedar Reserve, established in 1996, protects 550 square kilometers across the central Mount Lebanon range in the Chouf and Aley districts, making it Lebanon's largest nature reserve. Three separate cedar forests within the reserve—Barouk, Maasser el-Chouf, and Ain Zhalta-Bmahray—contain approximately 250,000 cedar trees across 3,000 hectares. The Barouk forest alone covers 700 hectares between 1,200 and 2,000 meters elevation. Unlike the ancient specimens at the Cedars of God, most Chouf cedars date from natural regeneration following reduced human pressure in the 20th century, with age structure surveys showing the majority under 200 years old. The reserve's elevation range from 1,000 to 2,000 meters creates habitat for 32 recorded mammal species, 200 bird species, and over 500 plant species. Tannourine Cedar Reserve, declared in 1999, protects 60 square kilometers in northern Mount Lebanon, including the Hadath el-Jebbeh cedar grove at 1,400 to 1,800 meters.