The Atlas Mountains continue on the north, known as Tunisian Dorsale. They reach to the Gulf of Tunis on the north-east corner of the country. The highest peak of the country, 'Jabal Shanabi', is 1544 m. high and located in this mountain range near the Algerian border.
The 'Medjerda Valley' is situated to the north of Tunisian Dorsale and hosts the main river system of the country. This river system rises in Algeria and drains into the Gulf of Tunis. This valley with its river system maintains the largest grain growing region in the country since the Roman times. The waters of the river system are used for electricity generation and irrigation.
The south of the country is covered with only the deserts. The area between the fertile north and this desert area is approximately 400 m. high treeless plain and some salt lakes before the desert. These plains and the edge of the desert areas are one of the most important tourist attraction areas of the country. The oases in the desert area also fantastic. The sand desert covering the southern tip of Tunisia continues to Algeria.
The total area of Tunisia is 163,610 square km. The distance from east to west is 378 km, and north to south 781 km.
Tunisia borders on Libya to the south-east and Algeria to the west. The ragged 1400 km. long coastline forms the eastern and northern boundaries.