Tunisia is situated on the Mediterranean coast of North Africa, midway between the Atlantic Ocean and the Nile Delta. It is bordered by Algeria on the west and southwest and Libya on the south east. It lies between latitudes 30° and 38°N, and longitudes 7° and 12°E. An abrupt southward turn of the Mediterranean coast in northern Tunisia gives the country two distinctive Mediterranean coasts, west-east in the north, and north-south in the east.
Though it is relatively small in size, Tunisia has great environmental diversity due to its north-south extent. Its east-west extent is limited. Differences in Tunisia, like the rest of the Maghreb, are largely north-south environmental differences defined by sharply decreasing rainfall southward from any point. The Dorsal, the eastern extension of the Atlas Mountains, runs across Tunisia in a northeasterly direction from the Algerian border in the west to the Cape Bon peninsula in the east. North of the Dorsal is the Tell, a region characterized by low, rolling hills and plains, again an extension of mountains to the west in Algeria. In the Khroumerie, the northwestern corner of the Tunisian Tell, elevations reach 1,050 metres (3,440 ft) and snow occurs in winter.
The Sahel, a broadening coastal plain along Tunisia's eastern Mediterranean coast, is among the world's premier areas of olive cultivation. Inland from the Sahel, between the Dorsal and a range of hills south of Gafsa, are the Steppes. Much of the southern region is semi-arid and desert.
Tunisia has a coastline 1,148 kilometres (713 mi) long. In maritime terms, the country claims a contiguous zone of 24 nautical miles (44.4 km; 27.6 mi), and a territorial sea of 12 nautical miles (22.2 km; 13.8 mi).
Tunisia's climate is Mediterranean in the north, with mild rainy winters and hot, dry summers. The south of the country is desert. The terrain in the north is mountainous, which, moving south, gives way to a hot, dry central plain. The south is semiarid, and merges into the Sahara. A series of salt lakes, known as chotts or shatts, lie in an east-west line at the northern edge of the Sahara, extending from the Gulf of Gabes into Algeria. The lowest point is Chott el Djerid at 17 metres (56 ft) below sea level and the highest is Jebel ech Chambi at 1,544 metres (5,066 ft).