Mont-Saint-Michel

In a stone hall high in the abbey there is a wooden wheel taller than two men standing on each other's shoulders. Almost everyone who sees it assumes it is medieval, some monkish contraption for hoisting building stone up the cliff. It is not. It was installed in the nineteenth century, when the abbey was a prison, and the men who turned it were inmates. They stepped inside the rim, walked, and the rope winding onto the axle dragged a sledge up a stone ramp on the outer wall. Coal, firewood, sacks of grain: everything the prison ate came up that ramp on the legs of the people it held.

It is now one of the most photographed rooms on the island, and hardly anybody photographing it knows what it was for. Which is a fairly good summary of the place. Almost every stone on this rock was laid by someone who wanted it for a purpose the previous owner would not have recognised.

A Bishop And A Hole In A Skull

The founding story is a dream, told the same way for centuries. Aubert, bishop of Avranches, was instructed by the archangel Michael to build an oratory on the bare rock out in the bay. He ignored it. He was told again. He ignored it again. On the third visit the archangel pressed a finger into his skull, and Aubert woke with a hole in his head.

There is a skull kept in a church in Avranches, traditionally identified as his, and it does have a round hole in the top of it. Nobody knows how the hole got there. What the story really records is a practical difficulty: the rock, then called Mont-Tombe, was a cold lump of granite in a bay with a lethal tide, and you do not build there unless you have an argument nobody can refuse.

The oratory went up early in the eighth century. Around 966 the Duke of Normandy installed Benedictine monks, and construction did not seriously stop for the next five hundred years.

Building Flat On Top Of A Point

The engineering problem was blunt. A church wants a broad, level floor. A granite peak does not offer one. Eleventh-century builders solved it by wrapping the summit in crypts and undercrofts, so the abbey church does not sit on the rock so much as on a stone basket built around it. Go down into the lower levels today and you find squat, enormously thick columns holding up a nave you cannot see from there.

In 1204 Breton troops sacked and burned the mount. The French king sent money to repair the damage, and what rose on the north face was a three-storey Gothic block called La Merveille, the Marvel: an almshouse at the bottom, a knights' hall in the middle, and the monks' cloister on the roof, stacked on the edge of a cliff over the sea.

Through the Hundred Years' War the island became a garrison. The English besieged it for years, from land and from water, and never got inside. Two heavy bombards left behind by the besiegers still sit at the gate.

After the Revolution the monks were expelled and the abbey was converted into a prison, which it stayed for roughly seventy years. It closed in 1863, was declared a historic monument in 1874, and has been under some form of restoration ever since. The gilded statue of Michael went up on the new spire in 1897, its tip about a hundred and seventy metres above the bay.

Now

The tidal range here is among the largest in Europe, swinging close to fourteen metres on spring tides. The bay empties for kilometres and then refills. In places the wet sand behaves like a trap, which is why walking out without a guide is genuinely dangerous rather than picturesquely dangerous.

A causeway built in 1879 disrupted the currents and the bay began silting up around the rock; slowly, Mont-Saint-Michel was being glued to the mainland. A long engineering project reversed it: a dam on the Couesnon river now stores water and releases it with the tide to flush sediment back out, the causeway was removed, and a bridge on slender piers opened in 2014 in its place. Water runs all the way around again.

It has been a World Heritage Site since 1979, and a small religious community still lives in the abbey. About thirty people live on the rock full-time, sharing it with several million visitors a year.