Take a tour of Château d'If in Marseille, France – part of the World’s Greatest Attractions series by GeoBeats. Jumping straight off the pages of Alexandre Dumas's Count of Monte Cristo is the Chateau D'If. This formidable structure dates its construction back to the 16th century. It was originally built as a fortress to guard Marseille against naval attacks. It became a famous prison where many criminals, most of whom died, were incarcerated. Despite its fearsome reputation, the Chateau D'If commands a lovely view of Marseille and the Mediterranean. Today, visitors can take a boat ride out and walk the halls of the supposedly inescapable prison.