Board the ferry at Nice's port in the morning and cruise out onto the Mediterranean Sea toward the Lérins Islands. Your destination: Ile Sainte-Marguerite, the largest island in the archipelago, known for its lush vegetation, heavily wooded forests and the legendary fortress prison, Fort Royal. Enjoy beautiful views across the French Riviera during your 1-hour crossing. Disembark on the island and spend the rest of the day exploring at your leisure. All activities and purchases are at your own expense. Well-marked walking trails criss-cross the entire island, taking visitors on a botanical and historical discovery. Pine and eucalyptus fragrances dominate these lovely hikes, suitable for most fitness levels. Enter the Fort Royal, a fortress built by the Spanish in the 17th century when the islands were under their control. Legend has it that the notorious 'Man in the Iron Mask' prisoner was held here in the late 1600s. Today the Fort Royal is home to a maritime museum, whose wealth of archaeological finds includes 1st-century murals, contents from a 10th-century Saracen shipwreck and many pieces from the Roman era, offering insight into Ile Sainte-Marguerite’s ancient history. Perhaps pay a visit to the Méditerranoscope, a marine study center dedicated to protecting the marine life beneath the waves around the Lérins Islands. Stroll to the Batéguier pond to see tons of migratory bird species, or head to the Point de la Convention, showcasing a range of unique plant species that have made a home on Ile Sainte-Marguerite. There are two restaurants on the island for lunch and two sandwich kiosks for a light snack. In the early evening, re-board the ferry for the 1-hour cruise back to Nice.