Grotte de la Baleine

Cassis is a small port on the Mediterranean coast east of Marseille, and it is known for white wine, painters' light and above all for the calanques, the steep limestone inlets that cut into the coast between here and Marseille.

The cliffs here are made of hard white limestone, riddled by cracks and hollows that the sea has widened over thousands of years. Along the shoreline, the waves and the dissolving action of water on limestone have carved caves at the foot of the cliffs, some open to the sea and some reached only by boat. Their interiors are often cool and quiet, with smooth walls, and the light changes dramatically with the sun, turning the water inside to a vivid green or blue. Caves and rock arches are among the most photographed features of the coast, and they have inspired many nicknames based on resemblances to animals and objects.

The best way to see sea caves around Cassis is from the water. Boat trips leave from the Port de Cassis and run along the coast into the calanques, such as Port-Miou, Port-Pin and En-Vau, passing under cliffs and showing the openings in the rock. Kayaking and diving are also popular, and local diving clubs lead dives into submerged caves, though these require training and local guidance. Weather and sea conditions matter, and trips are cancelled when the wind is strong. The coast is part of the Calanques National Park, which has rules to protect it, and in summer access to some areas is restricted for fire risk.

The town gives context. The Cap Canaille, a red-orange cliff just to the east, is among the highest sea cliffs in mainland France, and the Cassis Lighthouse stands at the end of the harbour jetty. The Port de Cassis is lined with pastel houses and cafés, the Église Notre-Dame-de-la-Garde and the Musée de Cassis give local history, and the Cassis Market in the Place du Marché sells local produce. The beach of Plage de la Grande Mer is the main town beach.

It suits boat-trip fans, swimmers and photographers. Before you go, check locally which caves can be visited and by which means, and book boat tours ahead in summer.