With over 60 protected buildings, Mont Saint-Michel and its beautiful bay have a rightful place on the UNESCO list of World Heritage Sites. It’s a picture perfect island 600 metres off the French coast. Many pilgrims en route to the abbey were able to access it easily at low tide. At high tide however, the crashing waves and cold waters made the island unreachable. The Mont was unconquered throughout the the Hundred Years War, and thanks to its impenetrability, the abbey was later used as a prison.