The famous island fort facing Marseille immortalised by Alexander Dumas in The Count of Monte Cristo. The castle was built by François I in 1529 and over the centuries it gained a fearsome reputation as many opponents of royal power were jailed and died in the fortress. A prison from 1541, it housed the most famous prisoners in the history of France, including the Comte de Mirabeau, incarcerated on the orders of his father, the famous Physiocrat. The Castle of If has been perfectly preserved and is one of the most impressive historical sites on the Mediterranean coastline.