Tunisia, with a surface area of 164,418 km², is in North Africa, between the Mediterranean Sea and the Sahara desert, and between Algeria and Libya. About 40% of it is desert, and the remainder is made up of fertile lands.
In the north there are mountains and the climate is temperate, with mild, rainy winters and hot, dry summers. Temperatures in the north range between 34 and 6ºC. In the south there are deserts leading down to the Sahara.
Southern Tunisia is arid, but in the north there are pine forests, with pastures for cattle in the northwest and orchards and vineyards along the eastern coast. Only 19% of the land can be cultivated, although 13% of this is irrigated. The highest peak in Tunisia is Jebel Chambi, to the north of the city of Kasserine, at 1,544 m.
Tunisia can be divided from north to south into various topographic regions that are easy to distinguish.
Starting in the north and going southwards, there is a series of mountain ranges including the Atlas in the Tell region, occupying the northern half of the country and crossing it from south-west to north-east, with elevations ranging between 610 and 1,544 metres, the latter being Tunisia’s highest point (Jebel Chambi). In these territories, there are both fertile valleys and plateaux with mountains. This is the starting-point for Tunisia’s longest river, the Majardah, which flows from west to east into the Gulf of Tunisia.
Towards the south, the landscape changes, with the mountains giving way to a plateau at an average altitude of 610 metres. This gradually drops down to an area of salt lakes, known as shatts o chotts, which stretch from east to west and are mostly at sea level. The most important of these lakes are the Djerid and Bizerta. This area is semi-desert steppe. In the southernmost part, the shatts end up at the Sahara desert, which occupies 40% of the total surface area of Tunisia. In the area between the shatts and the desert, there are many oases, especially around the city of Gabes which lies at the centre of the gulf of the same name, close to the frontier with Libya. About 400,000 date palms flourish in this area of large oases.
To the north, Tunisia borders with Algeria. The frontier is one of rough terrain in the area of the Atlas mountains, except for the northernmost part where it is formed by the El Kala natural park in Algeria. These natural frontiers continue all along the mountain range that crosses Tunisia, but when it descends and merges into the Sahara desert or, more specifically, at the Grand Erg Oriental, the frontier with Algeria becomes a straight line because there are no geographic features that can form a frontier. The frontier with Libya is mostly marked by high plains in the Libyan region of Tripolitania. According to WWF, the Tunisian territory comprises five ecoregions:
- North African montane woodlands in the North-western mountains
- North African Mediterranean woodlands along the coast and in the northern half of the country
- Mediterranean shrubland steppe in the centre
- North Saharan steppe in the southern half
- Saharan saltmarshes in several wetlands in the centre and north of the country