The Calanques is a small massif along the French Riviera, between Marseille and Cassis, barely 20 km long and 3 km wide. The highest point of the Calanques is Mont Puget (565 m).
A calanque is a deeply carved valley, with steep walls, rising from the blue water. It consists mainly of hard white limestone. The limestone is porous. The water seeps through it quickly, leaving little room for vegetation.
There are a variety of trails through the Calanques. The GR51 (also referred to as the GR 98) runs from Marseille to Cassis along the coast. The total length is about 20 kilometers long and by its difficulty rather too long for a day trip. However, there are several options to split it into pieces.
The area of the Calanques is managed by the Office National des fôrets. During the summer, the area can be closed because of the fire hazard. One site reports that in 2006 the historic hiking trails through the area apparently were destroyed because they became too dangerous. On our walks (in April) however, we didn’t encounter any problem. There was only one indication that the GR51 was interrupted in one place, but with an alternative route.
If you prefer not to walk, you choose for a boat trip along the Calanques. In the port of Cassis you can choose a tour of either 3, 5 or 8 Calanques.