The area of Lebanon is approximately 10,452 square kilometers. The country is roughly rectangular in shape, becoming narrower toward the south and the farthest north. Its widest point is 88 kilometers, and its narrowest is 32 kilometers; the average width is about 56 kilometers.

The physical geography of Lebanon is influenced by natural systems that extend outside the country. Thus, the Beqaa Valley is part of the Great Rift system, which stretches from southern Turkey to Mozambique in Africa. Like any mountainous country, Lebanon's physical geography is complex. Land forms, climate, soils, and vegetation differ markedly within short distances. There are also sharp changes in other elements of the environment, from good to poor soils, as one moves through the Lebanese mountains.

A major feature of Lebanese topography is the alternation of lowland and highland that runs generally parallel with a north-to-south orientation. There are four such longitudinal strips between the Mediterranean Sea and Syria: the coastal strip (or the maritime plain), western Lebanon, the central plateau, and eastern Lebanon.

The extremely narrow coastal strip stretches along the shore of the eastern Mediterranean. Hemmed in between sea and mountain, the sahil, as it is called in Lebanon, is widest in the north near Tripoli, where it is only 6.5 kilometers wide. A few kilometers south at Juniyah the approximately 1.5-kilometer-wide plain is succeeded by foothills that rise steeply to 750 meters within 6.5 kilometers from the sea. For the most part, the coast is abrupt and rocky. The shore line is regular with no deep estuary, gulf, or natural harbor. The maritime plain is especially productive of fruits and vegetables.

The western range, the second major region, is the Lebanon Mountains, sometimes called Mount Lebanon, or Lebanon proper before 1920. Since Roman days the term Mount Lebanon has encompassed this area. Antilibanos (Anti-Lebanon) was used to designate the eastern range. Geologists believe that the twin mountains once formed one range. The Lebanon Mountains are the highest, most rugged, and most imposing of the whole maritime range of mountains and plateaus that start with the Amanus or Nur Mountains in northern Syria and end with the towering massif of Sinai. The mountain structure forms the first barrier to communication between the Mediterranean and Lebanon's eastern hinterland. The mountain range is a clearly defined unit having natural boundaries on all four sides. On the north it is separated from the Nusayriyah Mountains of Syria by An Nahr al Kabir (the great river); on the south it is bounded by Al Qasimiyah River, giving it a length of 169 kilometers. Its width varies from about 56.5 kilometers near Tripoli to 9.5 kilometers on the southern end. It rises to alpine heights southeast of Tripoli, where Al Qurnat as Sawda (the black nook) reaches 3,360 meters. Of the other peaks that rise east of Beirut, Jabal Sannin (2,695 meters) is the highest. Ahl al Jabal (people of the mountain), or simply jabaliyyun, has referred traditionally to the inhabitants of western Lebanon. Near its southern end, the Lebanon Mountains branch off to the west to form the Shuf Mountains.

The third geographical region is the Biqa Valley. This central highland between the Lebanon Mountains and the Anti-Lebanon Mountains is about 177 kilometers in length and 9.6 to 16 kilometers wide and has an average elevation of 762 meters. Its middle section spreads out more than its two extremities. Geologically, the Beqaa is the medial part of a depression that extends north to the western bend of the Orontes River in Syria and south to Jordan through Al Arabah to Al Aqabah, the eastern arm of the Red Sea. The Beqaa is the country's chief agricultural area and served as a granary of Roman Syria. Beqaa is the Arabic plural of buqaah, meaning a place with stagnant water.

Emerging from a base south of Homs in Syria, the eastern mountain range, or Anti-Lebanon (Lubnan ash Sharqi), is almost equal in length and height to the Lebanon Mountains. This fourth geographical region falls swiftly from Mount Hermon to the Hawran Plateau, whence it continues through Jordan south to the Dead Sea. The Barada gorge divides Anti-Lebanon. In the northern section, few villages are on the western slopes, but in the southern section, featuring Mount Hermon (286 meters), the western slopes have many villages. Anti-Lebanon is more arid, especially in its northern parts, than Mount Lebanon and is consequently less productive and more thinly populated.

_{Source: Federal Research Division - Library of Congress (Edited by Thomas Collelo, December 1987)}