Tunisia can be broadly divided into four distinct topographical regions. In the north of the country lie the low ranges of the Atlas Mountains crisscrossing the country from the southwest to the northwest. These mountain ranges flatten out on to the fertile valleys and water fed plains of the Medjerda Valley. Tunisia has only one permanent river, the Majardah. The Majardah traverses the region from west to east, before its confluence with the waters of the Gulf of Tunis.
Tunisia's Mediterranean coast is characterized by a series of indentations and inlets that form natural harbours, coves and bays; the most important of them being the Gulfs of Tunis, Hammamet, and Qabis. The islands of Jarbah (Djerba) and Qarqanah (Kerkennah) lie in the Gulf of Gabes. The total length of coastline is 1,150 km. The north coast is Tunisia’s green belt with the fertile coastal plain backed by the densely forested Krounirie Mountains.
In the southern part of the country lies a 2000m high plateau. On its far side, the plateau wanes off into a series of shallow salt lakes called ‘shatts’ in the local lingo. These extend towards the sandy desert on the edges of the Sahara called the Grand Erg Oriental.