This magnificent UNESCO-protected Gothic cathedral, with its carved portals and three-tiered flying buttresses, would be a stunning sight even without its legendary stained-glass windows—though the world would be a drearier place. For these ancient glass panels are truly glorious: a kaleidoscope of colors so deep, so rich, and so bright, it’s hard to believe they are some 700 years old. Meant as teaching devices more than artwork, the windows functioned as a sort of enormous cartoon, telling the story of Christ through pictures to a mostly illiterate populace. From its beginnings, pilgrims came from far and near to see a piece of cloth that believers say was worn by the Virgin Mary during Christ’s birth. The relic is still here, but these days it’s primarily a different sort of pilgrim that is drawn to Chartres: More than 1.5 million tourists come here every year to admire the magnificent edifice.

A Romanesque church stood on this spot until 1194, when a fire burnt it virtually to the ground. All that remained were the towers, the Royal Portal, and a few remnants of stained glass. The locals were so horrified that they sprung to action; in a matter of only 3 decades a new cathedral was erected, which accounts for its remarkably unified Gothic architecture. This was one of the first churches to use buttresses as a building support, allowing the architect (whose name has been lost) to build its walls at twice the height of the standard Romanesque cathedrals and make space for its famous windows. The new cathedral was dedicated in 1260 and has miraculously survived the centuries with relatively little damage. The French Revolution somehow spared the cathedral. During World War I and World War II, the precious windows were carefully dismounted piece by piece and stored in a safe place in the countryside.

Before you enter the church, take in the facade, a remarkable assemblage of religious art and architecture. The base of the two towers dates from the early 12th century (before the fire). The tower to your right (the Old Tower, or South Tower) is topped by its original sober Romanesque spire; that on your left (New Tower, or North Tower) was blessed with an elaborate Gothic spire by Jehan de Beauce in the early 1500s, when the original burned down. Below is the Royal Portal, a masterpiece of Romanesque art. Swarming with kings, queens, prophets, and priests, this sculpted entryway tells the story of the life of Christ. The rigid bodies of the figures contrast with their lifelike faces; it is said that Rodin spent hours here contemplating this stonework spectacle. You can climb to the top of the New Tower to take in the view on a guided visit only; just remember to wear rubber-soled shoes—the 300 steps are a little slippery after all these centuries.

Once inside the cathedral, you’ll really understand what all the fuss is about. The dimness is pierced by the radiant colors of the stained-glass windows, which shine down from all sides. Three windows on the west side of the building, as well as the beautiful rose window to the south called Notre Dame de la Belle Verièrre, date from the earlier 12th-century structure; the rest, with the exception of a few modern panels, are of 13th-century origins. The scenes depicted in glass read from bottom to top and recount stories from the Bible as well as the lives of the saints. You will soon find yourself wondering how in the world medieval artists, with such low-tech materials, managed to create such vivid colors. The blues, in particular, seem to be divinely inspired. In fact, scientists have finally pierced at least part of the mystery: The blue was made with sodium and silica compounds that made the color stand up to the centuries better than glass made with other colors.

Another indoor marvel is the chancel enclosure, which separates the chancel (the area behind the altar) from the ambulatory (the walkway that runs around the outer chapels). Started in 1514 by Jehan de Beauce, this intricately sculpted wall depicts dozens of saints and other religious superstars in yet another recounting of the lives of the Virgin and Christ. Back in the ambulatory is the Chapel of the Martyrs, where the cathedral’s cherished relic resides: a piece of cloth that the Virgin Mary supposedly wore at the birth of Christ, which was a gift of Charles the Bald in 876.

Chartres also harbors a rare labyrinth, which is traced on the floor of the cathedral near the nave. A large circle, divided into four parts, is entirely filled by a winding path that leads to the center. In the Middle Ages, these labyrinths represented the symbolic path that one must follow to get from earth to God; pilgrims would follow the path while praying, as if they were making a pilgrimage to Jerusalem. Note: The cathedral asks that visitors not talk or wander around during mass, which is generally held in the late morning and early evening. You are welcome to sit in on services, of course.

Tours, Guided & Otherwise

For more than 3 decades, Malcolm Miller has been studying the cathedral and giving guided tours in English. His rare blend of scholarship, enthusiasm, and humor will help you understand and appreciate what you are looking at. From Easter through October, his 75-minute tour begins at noon Monday through Saturday (10€). From May through September, his colleague, Anne Marie Woods, leads a second tour at 2:45pm. No need to reserve; a sign at the meeting point inside at the entrance to the cathedral’s gift shop indicates that day’s tour schedule. You can also rent an audioguide (in English) for 6.20€.