From quai des Belges at the Vieux Port, you can take a 20-minute motorboat ride to Château d'If for 10€ ($13) round-trip. Boats leave every 30 to 45 minutes, depending on the season. For information, contact the Veolia Company, quai des Belges (tel. 04-96-11-03-50). On the sparsely vegetated island of Château d'If (tel. 04-91-59-02-30 for information), François I built a fortress to defend Marseille. The site later housed a prison, where carvings by Huguenot prisoners can still be seen. Alexandre Dumas used the château as a setting for the fictional adventures of The Count of Monte Cristo. The château's most famous association -- with the legendary Man in the Iron Mask -- is also apocryphal. The château is open daily from 9am to 5:30pm (until 7pm Apr-Sept). Visitors pay 5€ ($6.50) to enter the island.