If Castle is on the eponymous island, in the middle of the bay of Marseilles. To visit, you have to take a boat from the old harbour pier. It takes about 20 minutes to get there, and about 45 back because it passes by the island of Friuli. It has been declared a National Monument and was built by Francis I to protect the coast. From 1580 to 1871 it was a prison for its strategic and impregnable position. It has three towers, most notably the Tower of San Cristobal, which stands at 22 meters. But what makes this castle world famous is the fact that Edmond Dantes, the Count of Monte Cristo, was imprisoned here.