Start your boat tour from Marseille's old port. Cruise south in a quiet hybrid-electric boat across the beautiful Bay of Marseille. Learn about the city's history and its main monuments on your way to the national park. Arrive at the gates of Calanques, la Baie des Singes (Monkeys Bay). Follow the scenic passage between Maïre Island and the Croisette Cap. Start your boat trip along Calanques's 20-kilometer (12-mile) stretch of coastline, between the village of Les Goudes and the town of Cassis. Admire the majestic scenery, from the limestone cliffs overlooking untouched inlets to the tiny fishing ports dotted with little cabanons (traditional Provençal cabins). During the boat tour, enjoy free to swim and explore the underwater world, as well as rest and have a pleasant lunch onboard. See why Calanques got its name from the Provençal word, "calanco", for a valley carved by a river before reaching the sea and discover the park's caves. See the paleolithic Cosquer Cave, the Blue Grotto, and the Capelan Cave. Spot the numerous fossils encrusted in the limestone.  Learn about how the fossils were formed one hundred million years ago with the accumulation of sediment in the seabed and then pushed up during the Tertiary Period, when the Alps took shape. Look at how erosion has accentuated rocky rifts and given birth to the rugged landscape you see today.