Up until a few years ago, quirky Mont St. Michel, a tidal island (tides vary as much as 50 feet) located off the coast of Normandy, France, was in danger of losing its maritime identity. In the 8th century, a bishop established a small chapel there. A Gothic abbey, used during the French Revolution as a prison, followed a few centuries later. Then in the 19th century a causeway connecting the island to the mainland was built, preventing the sea from washing away silt that collected around it.

Up until a few years ago, quirky Mont St. Michel, a tidal island (tides vary as much as 50 feet) located off the coast of Normandy, France, was in danger of losing its maritime identity. In the 8th century, a bishop established a small chapel there. A Gothic abbey, used during the French Revolution as a prison, followed a few centuries later. Then in the 19th century a causeway connecting the island to the mainland was built, preventing the sea from washing away silt that collected around it.