“One needs to be eight centuries old to know what this mass of encrusted architecture meant to its builders,” wrote Henry Adams in his book Mont-Saint-Michel and Chartres. And that was more than a hundred years ago. Mont-Saint-Michel has gone through several major transformations since Adams’ time and is in the midst of another one now that will change its meaning or meanings once again.

Mont-Saint-Michel has been so many different things in the course of its long life, since its founding in the early eighth century, when the Bishop of Avranches built a church dedicated to the archangel Michael on a rock of granite in the sea. It was originally the hopeful assertion of Christianity in a Europe that was still part pagan and vulnerable to Viking raids on the northern coasts of what is now France. Two centuries later, the Duke of Normandy gifted the site to the Benedictine monks, who began building an ambitious abbey church under the patronage of William the Conqueror—the expression of a richer, more confident era as the Normans (former Vikings) were about to set out on not only the conquest of England but also of Sicily and Southern Italy. The abbey atop the Mont became both a major pilgrimage site—there were even souvenirs sold here in the Middle Ages—and a locus of ecclesiastical and political power. It was also a major center of medieval learning, with a rich library and scriptorium. At the time of the Hundred Years’ War, the church evolved into a military citadel—an impregnable fortress in the sea—the only spot in Normandy that never fell to the English. During and after this conflict, Mont-Saint-Michel assumed many of its current features—the ramparts that line the handsome stone walls and (much later) the statue of St. Michael, the warrior angel who now stands atop a spire some 300 feet in the air, his sword held aloft and his heel crushing a dragon, representing Satan or sin.

Building on such treacherous ground—on a small rock in a bay that contains some of Europe’s strongest currents and most powerful tides—must have seemed like the ultimate act of faith. For the pilgrims flocking to pay homage to the archangel, the trip to reach this heavenly precinct was itself a true test of faith: Centuries ago the shore was a full seven kilometers (4.3 miles) from the island (five kilometers farther than it is today). One had to wait until low tide, when the sea receded and left a flat strand of grayish mud, and get the timing right. The crossing on foot could be dangerous—high tide can rise up to 45 feet and sweep in at some 200 feet per minute. Moreover, at low tide the gray, claylike sand can suddenly give way to pools of quicksand where an inexpert trekker can become trapped. In 1318, eighteen pilgrims drowned in the bay and another dozen died in the quicksand. Now there are organized treks with trained guides; even so, a group of tourists got caught in the sand last year and needed rescuing.

With time, Mont-Saint-Michel has lost more and more of its status as an island. The relentless flow of the tides, bringing in their wake alluvial soil ideal for the growth of vegetation, has left the soil near the shore extremely fertile. And the people of Normandy—like those in Holland—gradually started using dikes and irrigation systems to reclaim land, pushing out the edge of the shore and bringing more of the land by the sea under cultivation. The salty grass that grows on the sandy ground as the sea recedes makes for excellent grazing, and the sheep raised in the area—les agneaux de prés-salés (salty pasture sheep)—are treasured for their flavor. The buildup had pushed its way to within two kilometers of Mont-Saint-Michel by the 19th century and might have reached all the way had there not been a movement to stop it and preserve the island nature of the ancient church.

With the French Revolution, the Abbey of Mont-Saint-Michel was closed—like many church buildings—and it was turned into a prison. “What a strange place is this Mont-Saint-Michel!” wrote Victor Hugo, in 1836. “All around us, as far as one can see, infinite space, the blue horizon of the sea, the green horizon of the earth, clouds, air, freedom, birds in full flight, ships with full sails; and then, all of a sudden, there, in the crack of an old wall, above our heads, through a barred window, the pale face of a prisoner.” In a poem, he called it the “pyramid” of the seas.

In 2005, the French government, which owns the abbey, began work on a major project to “restore the maritime character” of Mont-Saint-Michel. The buildup of silt was gradually reducing the parts of the bay that filled up with water at high tide, and, according to some studies, if nothing was done, the island would find itself permanently connected to the mainland by 2040. The French central state, together with the regional governments of Normandy and Brittany (Mont-Saint-Michel is technically in Normandy but the Bay of Mont-Saint-Michel is shared by both regions) and the European Union, undertook a massive and expensive renovation project budgeted at nearly $300 million. The main features of the project include: the destruction of the old causeway to allow the sea to move freely around Mont-Saint-Michel and the construction of a light bridge or walkway in its stead; a dam on the Couesnon River to hold water during high tide and then release it when the tide recedes, to push sand away from the island; the destruction of a large parking lot at the foot of the Mont and the construction of a parking area on the mainland with a shuttle bus service to bring tourists and employees to and from the island.

The initial impression of the place as one makes one’s way from the shuttle bus is decidedly more commercial than spiritual. The village of Mont-Saint-Michel, which grew up around the church, is tiny, with a full-time population of roughly 50. Its narrow, medieval streets are quickly crowded with tourists, who, shoulder to shoulder, four or five thick, mill about like subway commuters at rush hour along the main street, which is nonstop cafés, hotels, restaurants and shops, selling every kind of souvenir imaginable: key rings, paperweights, potholders, T-shirts, bowls, cups, postcards, caps, pencils, dishes, place mats. The food is mostly bad and overpriced. Almost every other place bears the name La Mère Poulard, the town’s most famous restaurant and the flagship business of Eric Vannier, the former mayor (he just stepped down) and the island’s biggest businessman. Along with numerous hotels and restaurants, he has started a successful brand of Mère Poulard biscuits, cakes and cookies. The brand is so ubiquitous in Mont-Saint-Michel that Vannier is widely, and usually not affectionately, known as Mayor Poulard, which in French (Maire Poulard) sounds almost exactly like Mère Poulard. The omelettes at La Mère Poulard cost between €24 and €49 ($33 to $68). It must be quite an omelette.

***

Among its many meanings, Mont-Saint-Michel is the goose that laid the golden egg. Designated a World Heritage site by Unesco, Mont-Saint-Michel has between 2.4 and 2.8 million visitors per year. With each tourist leaving behind about $25, that means an annual flow of some $63 million into a tiny town of 247 acres, about one-third of a square mile. The French state has 99 official national monuments. “Five sites pay for the upkeep of the other 94,” explains Jean-Marc Bouré, the former administrator of the historic site of the abbey. And yet only 1.2 million of the 2.4 million to 2.8 million visitors actually take the trouble to visit the abbey, which is at the top of Mont-Saint-Michel. The other 1.2 million to 1.6 million are spending their time and money in the shops and restaurants, as well as four “historical museums,” cheesy establishments with wax figures emphasizing the more lurid aspects of the local history with a heavy emphasis on the prison and the more brutal forms of torture once practiced there. Three of these museums are owned by the former Mayor Poulard. When Bouré proposed allowing tourists to buy tickets to the abbey down at the parking area or at the foot of Mont-Saint-Michel, Vannier helped block the initiative.

In some ways, the trip to the top offers a modern version of the medieval journey through life—a kind of Divine Comedy. The way up is demanding: One must pass through the tourist hell of the town below and make one’s way up the increasingly steep ascent to the abbey, where many must pause to catch their breath after one or other of a seemingly infinite set of stairs. As one ascends, the crowd thins, discouraged by the demanding climb, the lack of shops and cafés, or simply held in thrall by the distractions below. Suddenly, as one approaches the top, the views open up—the horizon widens; one can see the immense and gorgeous bay; the sand and water glisten in the sun. There is quiet other than the occasional cries of seabirds.

The climb is well worth the effort. The abbey is one of the great living expressions of European medieval architecture. The builders’ genius was called forth by the extreme difficulties of constructing a massive complex on the narrow summit of a jagged piece of granite rock some 260 feet up above the sea. Had the abbey been built on flat ground, it would no doubt have been a large, horizontal complex of buildings with a church, courtyards, cloisters and so forth all on the same level. Instead, there was not enough room for a large church on the top of the mountain. But rather than build a small one, they built into the side of the mountain an ingenious, massive structure on three levels. The church—appropriately—sits atop the whole structure, opening onto a terrace with amazing views. But only about half of it sits solidly on rock; the other half, called the choir, is perched somewhat perilously on top of the two levels of buildings below.

The original building held up for about 400 years, from the time of William the Conqueror in the 1050s until about 1420, when its massive Norman pillars crashed down into the monks’ dormitory below, fortunately killing no one. And so, all that is left of the original church is three gorgeous sculpted Norman columns, whose graceful, sober simplicity and strength are the architectural equivalent of the army of 40,000 knights with which its patron, William the Conqueror, crossed the English Channel and conquered England. The choir was rebuilt in the late 1400s in a different style that the French call gothique flamboyant (flamboyant Gothic), with high, slender, delicately carved arches and tall bays of stained glass windows that flood the front of the church with light.

Although separated by nearly half a millennium, the two halves of the church seem remarkably harmonious. It is only after a while, and perhaps a guided tour, that one becomes aware that they are quite different. As Henry Adams wrote: “Although the two structures are some five hundred years apart, they live pleasantly together....The choir is charming—far more charming than the nave, as the beautiful woman is more charming than the elderly man.”

Just beyond the choir is the magnificent 13th-century, three-story structure built into the steep northern slope of the Mont known as La Merveille (the Marvel). It contains a gorgeous cloister with a double row of delicately carved arches and a refectory where the powerful abbots once entertained and where (in Henry Adams’ account) jongleurs would have recited The Song of Roland for the entertainment of the assembled company. Underneath is a handsome and well-lit room that served as the abbey’s scriptorium, where monks copied manuscripts, for the abbey’s famous library. In the cellar is an enormous wooden wheel that served, among other things, as a winch to haul water and other supplies up the north side of the Mont. It is sobering to recall that virtually all of the stone and building materials were brought here by boat, much of it hauled up from the sea by rope. The vast cavernous lower depths of the abbey complex also served as a prison. Even as early as the 15th century, the kings of France supposedly sent prisoners here. According to our tour guide, some prisoners spent their days turning the massive wheel to haul goods up to the abbey.

***

Today, the abbey is shared by something of an Odd Couple pair of occupants: the very secular French state, in the form of the administrator in charge of Mont-Saint-Michel as a national monument, and the Monastic Fraternity of Jerusalem, a French religious order that has occupied the abbey since 2001 and pays a nominal rent to the government. For the most part, the two get along. But the state has an economic interest in getting as many people as possible to take the official tour through the abbey (€9, or $12) as well as use the site for concerts and cultural events; the monks and nuns view the abbey as a religious setting, and no tours are conducted during religious services, which occur three times a day.

The fraternity rents a couple of guesthouses to pilgrims who come on retreat. It was here that I stayed during a weekend spiritual retreat. The demands of the retreat were not especially onerous. I and my fellow participants were free to come and go as we pleased. We were encouraged to attend the three religious services with the brothers and sisters each day and to share a modest meal in their refectory. I skipped the morning service two of the three days but attended the afternoon and evening services and ate with the monks.

Even so, the monastic life seemed a very challenging one. The monks’ and nuns’ day was long and arduous, getting up at 5:30 for an hour of silent prayer before the morning service at 7 on weekdays—an hour later on weekends. After the service, the two groups ate separately (except on very special occasions), each in their own refectories with a few outside guests. Conversation was strictly forbidden in the dining room and at first it seemed rather lonely to be in this spartan refectory—each eating his humble repast while inside his own world of thoughts or prayers. The monks were friendly and kind in the limited moments when conversation was possible—right after Mass or after we had left the dining room. On Saturday, we took coffee out in a little garden with marvelous views of the bay, and the monks chatted amiably. But conversation is highly circumscribed by the extreme rigor of their lives. When I asked Brother Lauren-Nicholas, the monk who was in charge of the guesthouse, what life path had brought him to the religious order, he politely but firmly rebuffed the question: “Since I have not shared my personal journey even with my brothers here, I am afraid I will have to keep that to myself,” he said, but then added with a smile, not wanting to offend: “What matters is the present.”

Life at the abbey appears to be entirely divorced from the touristic hubbub of the town below. Brother Lauren-Nicholas half-jokingly refers to the worship of Mammon going on at the bottom of the hill.

The small community of people who live between the abbey and the shops feel angry and betrayed by the changes taking place in and around Mont-Saint-Michel. “This whole project has been driven by the idea of turning Mont-Saint-Michel into a picture postcard—the island with water around it—and not a place where people actually live,” says Jean-Yves Lebrec, whose old family home sits halfway up the hill to the abbey. Outside his house is a large banner with the words “Stop the Massacre of the Rock!” It refers to a large concrete platform cut out of the rock for emergency vehicles. The platform was required as a matter of public safety by the French government, necessitated, somewhat ironically, by another feature of the plan, a ford that will be submerged in water at the very highest tides. The feature was visually appealing but created a potentially dangerous situation: tourists needing medical attention being unable to leave the island. (Amphibious emergency vehicles can still travel between the island and mainland at all times.) “And so,” Lebrec continues, “they are actually damaging the thing they are supposed to be preserving: Le Mont.”

“Life here has become impossible,” says Géraldine Faguais-Ridel, owner of a small souvenir shop and a member of the municipal council. “We feel as if we have been taken hostage by forces that have not taken our lives into consideration at all.” The parking lot that had allowed residents to drive back and forth to fetch groceries or supplies has been eliminated. They are now forced to take shuttle buses, often walking with their bundles in the cold and rain. Weather on the Normandy coast is blustery and wet. The new shuttle bus stop was originally placed nearly a kilometer from the new mainland parking lot, making daily life a mess for people working or living on the island.

It did not escape people’s notice that the placement of the shuttle stop forced tourists to walk past establishments owned by Vannier, the businessman and former mayor, and bypassed the shops and restaurants of one of his chief rivals. Vannier was taken to court and fined €30,000 ($41,000). (He is appealing the case.)

The shuttles now drop passengers off closer to the island. At the continent end of the route, the shuttle bus stop was also moved closer to the parking lot. The daily parking fee increased from €8.5 to €12 (about $17), a rather hefty sum for a few hours of parking in rural Normandy. (The workers at the abbey staged a three-week strike last year to protest the rising costs.) Even with the improved shuttle service it still takes a good half-hour to travel the three kilometers from town to the parking lot.

That Mont-Saint-Michel has been transformed from a town into a kind of medieval stage set is demonstrated by one of ex-mayor Vannier’s latest commercial strokes of genius: a business that puts on mock Western weddings for Japanese tourists. The former mayor’s maitre d’hotel dons the garb of a priest and performs these ceremonies for couples dressed up in Western wedding garb; then they are photographed and filmed feeding each other cake in front of the medieval walls. The idea seemed too preposterous to be true. But there it was—a small office nestled underneath one of Vannier’s other businesses in town—Les Terrasses Poulard. No customers were around when I visited in late October—not wedding season—but there was a friendly Japanese office manager, a mannequin of a bride wearing a Western-style wedding dress and a flat-screen TV playing the video of a Japanese couple’s “wedding” at Mont-Saint-Michel. The couples are generally not Christian and they are married legally back in Japan, the young woman explained. Holding a wedding ceremony—or having the video of a wedding ceremony—in Mont-Saint-Michel holds real cachet back in Japan, she said. “Japanese have very short vacations, usually a week, and so they have enough time for two things, Paris and Mont-Saint-Michel.”

While this might seem to signal the ultimate decline of Mont-Saint-Michel, it is important to remember that the island has had many low moments. According to my official guide, when the prison was in full swing, one man was kept for more than 20 years in a cage too small to allow him either to lie down or stand up. Compared with this, the fake Japanese weddings appear a little less dreadful. And to help put the current local discontent in perspective, Père André, parish priest of the Church of Saint Pierre, said the merchants of Mont-Saint-Michel protested when France closed the prison in 1863. The townsfolk did a lively business in providing food and lodgings for the family members of the prisoners who came to visit their loved ones.

In many ways, to appreciate Mont-Saint-Michel you must leave it. The atmosphere of the town—with its wall-to-wall tourism and fierce internecine political and commercial antagonisms—quickly becomes claustrophobic. What makes Mont-Saint-Michel so extraordinary is not just its architecture: It’s the architecture placed in an equally extraordinary natural site. The coming and going of the tide—the constant play of light on the water, on the glistening wet sand—means that Mont-Saint-Michel always looks different. One understands a bit how its spectacular rise from the sea reaching to the sky made Mont-Saint-Michel appear to some pilgrims like the new Jerusalem, a kind of heaven on earth to which they were drawn. Its majestic architectural palimpsest dominates the coastline of this part of Normandy and can be seen at a great distance inland. You can see it already from the highway; it seems to follow you over your shoulder when you drive between Normandy and Brittany.

***

Perhaps the best part of the current renovation project—and of the few parts that are finished—is a dam built near where the Couesnon River meets the sea just in front of Mont-Saint-Michel. Rather than hold the river water in, the new dam opens up to let the sea water enter at high tide and then releases it again at low tide in order to push water and sand out, relieving the buildup of silt around the Mont. Although the dam has a practical aim, its architect, Luc Weizmann, also used great sensitivity and imagination to create one of the nicest public spaces in and around Mont-Saint-Michel. He built an attractive wooden viewing platform as well. It has a perfect, unobstructed view of Mont-Saint-Michel, and the dramatic moment in which the dam opens and releases a rush of water (usually once or twice a day) has become a popular tourist attraction—about the only free one in Mont-Saint-Michel.

Subtly and poetically, the dam project offers both a mirror and a reading of Mont-Saint-Michel. Harnessing the power of the sea to preserve Mont-Saint-Michel mimics, Weizmann explains, what the original construction of Mont-Saint-Michel did and what the archangel Michael with his foot on the dragon represents: a kind of triumph over the forces of chaos and evil. The enormous steel wheels that open and close the dam were designed to resemble the huge wooden power wheel inside the ancient abbey. Weizmann placed a handsome border of bronze at the front of the viewing platform, which picks up the bronze of the massive bell of Mont-Saint-Michel, and he inscribed letters from Greek, Latin, Hebrew and Arabic alphabets in the bronze. Weizmann took the lettering in part from the rich manuscript collection of the abbey, which is now in the nearby town of Avranches. Weizmann knows there is no such thing as recreating an eighth-century or a 14th-century church—only a respectful 21st-century reimagining.

Weizmann is also aware that the water coming from his dam is only a tiny factor pushing against the larger forces of nature at work in the bay. Many are skeptical of the work being done now to preserve the Mont’s “island character.” The buildup of sand, accumulating every day, at Mont-Saint-Michel is the inevitable result of the powerful force of the sea. “The tide coming in is stronger than the tide going out,” explains Patrick Desgués, the guide who leads me across the sandy marsh. “As a result, the tide leaves more sand than it carries away. So I don’t see how this project can reverse that,” he says as we walk across the beautiful claylike desert that forms as the sea recedes. In the background you can see a few pieces of earth-moving equipment—small against the horizon—working to encourage the water to flow back out on either side of Mont-Saint-Michel. Those human efforts seem puny in the face of the wide bay and the roiling sea.

“It’s a race against time,” admits Audrey Hémon, an engineer who works on the project, as we talk at the dam platform. The grassy patches in the sand have receded somewhat since the dam became operational, but no one knows whether the project will succeed in its ultimate goal: making sure that Mont-Saint-Michel will remain an island over the long term. “But we do know that if we do nothing, the shore will reach Mont-Saint-Michel.”