The Calanques—a 20-kilometer ribbon of vertical limestone stretching from Marseille to Cassis—remained inaccessible by road until the 1960s, when foot trails first opened to the public. Before that, fishermen and smugglers navigated these deep inlets by rowboat, exploiting blind coves and sea caves to evade customs patrols. The geological drama is the work of 100 million years: Urgonian limestone deposited in a shallow Cretaceous sea, then fractured and tilted by the collision of the African and European plates. Glacial meltwater carved the deep valleys; rising seas flooded them 12,000 years ago, leaving today's fjord-like calanques. In 2012, France designated 520 square kilometers of coast and hinterland as Calanques National Park, the first peri-urban national park in Europe and the only one with both terrestrial and marine protection zones. The park encompasses nine major calanques—Port-Miou, Port-Pin, En-Vau, Sormiou, Morgiou, Sugiton, Marseilleveyre, Callelongue, and Devenson—each with distinct geology and microclimate. En-Vau's 200-meter white cliffs and cobalt water draw climbers and kayakers; Sormiou's gravel beach hosts a dozen cabanons, working fishing huts dating to the early 20th century. The park's marine zone protects 60 fish species, red coral beds, and Posidonia seagrass meadows that stabilize the seafloor and sequester carbon at rates exceeding terrestrial forests. Access by land is limited by fire risk: the park closes trails when wind speed exceeds 40 kilometers per hour or humidity drops below 30 percent, typically 60 to 90 days per summer. Boat departures from Marseille's Vieux-Port bypass these restrictions, operating year-round except in heavy seas. Electric and sail-powered vessels dominate the fleet, enforcing the park's 5-knot speed limit within calanque waters. Most calanques boat tour from Marseille itineraries anchor in two or three coves for swimming and snorkeling, with guide commentary on geology, endemic flora such as Phoenician juniper and Aleppo pine, and the history of calanque settlements. Half-day tours concentrate on the nearest inlets—Callelongue, Marseilleveyre, Sormiou—while full-day sailings reach Cassis and the deeper calanques of En-Vau and Port-Pin, where turquoise water meets vertical limestone in compositions that have inspired painters from Cézanne to Derain.