A calanque is a steep-walled inlet, cove, or bay that is developed in limestone, dolomite, or other carbonate strata and found along the Mediterranean coast. A calanque is a steep-sided valley formed within karstic regions either by fluvial erosion or the collapse of the roof a cave that has been subsequently partially submerged by a rise in sea level.
The best known examples of this formation can be found in the Massif des Calanques in the Bouches-du-Rhône département of France. This range extends for 20 km in length and 4 km in width along the coast between Marseille and Cassis, culminating in Marseilleveyre (432 m) and Mont Puget (565 m).
The calanques between Marseille and Cassis are popular amongst tourists and locals alike, offering several vantage points (such as the Corniche des Crêtes and Cap Canaille) allowing spectacular panoramas. A great number of hikers frequent the area, following numerous pre-marked trails. The cliffs are also used as training spots for rock climbers. However, this excessive use has posed problems of potential damage to this delicate microhabitat.
Most of the calanques are also closed to the public during the summer (typically July through September) due to the risks of forest fire that often happen during the dry season.
The best time to visit calanques is probably March through May, when temperatures are still quite fresh and, unlike autumn and winter, rain is usually quite rare. As no fresh water sources are available in the calanques, it is advised to carry large supplies of water, especially during the hot summer to prevent serious dehydration.