Tunisia is located on the south Mediteranean shore with Algeria and Libya as its neighbours. Northern Tunisia, which runs along the eastward extension of the coastline from the Algerian border to Nabeul on the southern coast of the Cap Bon peninsula, consists of a mountainous coastal region which is bisected by the Majarda river valley. Around the coastal cities of Bizerta and Tunis are two small plains. The region as a whole is Tunisia’s most populous area and receives the highest levels of rainfall – between 1000 and 1500mm – which is particularly intense close to the Algerian border. Summers are dry and hot and winters are wet. The average rainfall over most of northern Tunisia ranges between 40 and 100 cm a year. The south is mostly desert and only enjoys about 20 cm a year.