L'Estérel is a small mountain range extending over 198 sq mi (320 km²) between Fréjus and La Napoule in the eastern part of the Var department, at the limit of the Alpes-Maritimes. With a length of 9.3 miles (15 km) and a width of 6.2 miles (10 km), it is limited west by the Argens valley and north by the Tanneron massif. L'Estérel steeply falls into the Mediterranean Sea. Only a narrow corridor between the reliefs and the coast allows the passage of the road and a railway line.