Château d'If

Lonely Planet review

Immortalised in Alexandre Dumas' classic 1840s novel Le Comte de Monte Cristo (The Count of Monte Cristo), the 16th-century fortress-turned-prison Château d'If sits on a 30-sq-km island, 3.5km west of the Vieux Port. Political prisoners of all persuasions were incarcerated here, along with hundreds of Protestants (many of whom perished in the dungeons), the Revolutionary hero Mirabeau, and the Communards of 1871.

A few hundred metres west of the Château d'If are the barren white-limestone islands of Ratonneau and Pomègues, collectively known as the Îles du Frioul. From the 17th to the 19th century, they were used as a place of quarantine for people suspected of carrying plague or cholera. Sea birds and rare plants thrive on these tiny islands (each about 2.5km long, totalling 200 hectares), which are sprinkled with the ruins of the old quarantine hospital, Hôpital Caroline and Fort Ratonneau (used by German troops during WWII).