The variation between high and low tides in the region of Normandy, France is the greatest in Europe, with a difference of up to 15 meters (46 ft) in levels between high and low water marks.
This mesmerizing phenomenon can be clearly seen if you visit Mont Saint-Michel. The rocky tidal island of 100 ha (247 acres) has a population of only 44 people, but its unique beauty guaranteed it a listing as a UNESCO World Heritage Site.
The 3 million tourists who visit Mont Saint-Michel each year can also witness the speed with which the tides rise and fall. So if you decide to visit, cross over the dry causeway and avoid walking across the sands from the neighbouring coast; since many a pilgrim, from medieval times to present-day, have been caught by these dangerous tides.