The center of pilgrimage of Benedictine.

Mont-Saint-Michel, rocky islet and famous sanctuary in Manche department, Normandy region, France, off the coast of Normandy. It lies 41 miles (66 km) north of Rennes and 32 miles (52 km) east of Saint-Malo. Around its base are medieval walls and towers above which rise the clustered buildings of the village with the ancient abbey crowning the mount.

Mont-Saint-Michel is almost circular (about 3,000 feet [900 metres] in circumference) and consists of a granite outcrop rising sharply (to 256 feet [78 metres]) out of Mont-Saint-Michel Bay (between Brittany and Normandy). Most of the time it is surrounded by vast sandbanks and becomes an island only when the tides are very high. Before the construction of the 3,000-foot causeway that connects the island to land, it was particularly difficult to reach because of quicksand and very fast-rising tides. The causeway, however, has become a barrier to the removal of material by the tides, resulting in higher sandbanks between the islet and the coast.

The island, which was fortified in 1256, resisted sieges during the Hundred Years’ War between England and France (1337–1453) and the French Wars of Religion (1562–98). The monastery declined in the 18th century, and only seven monks were living there when it was dissolved during the French Revolution (1787–99). It became a state prison under Napoleon I (reigned 1804–14/15) and remained a prison until 1863. In 1874 it was classified as a historic monument and restored.

One of the more popular tourist attractions in France, Mont-Saint-Michel was designated a UNESCO World Heritage site in 1979.