Looming above place du Parvis on the Ile de la Cité is the Cathédrale de Notre-Dame, the most enduring symbol of Paris. Begun in 1163, completed in 1345, badly damaged during the Revolution, and restored by Viollet-le-Duc in the 19th century, Notre-Dame may not be France's oldest or largest cathedral, but in beauty and architectural harmony it has few peers -- as you can see by studying the facade from the open square. The doorways seem like hands joined in prayer, the sculpted kings form a noble procession, and the rose windows gleam with what seems like divine light. Above, the gallery breaks the lines of the stone vaults, and between the two high towers the spire soars above the transept crossing. Seen from the front, the cathedral gives an impression of strength, dignity, and majestic serenity; seen from the Pont de l'Archevêché, it has all the proud grace of a seagoing vessel, the cross on its steeple borne like the flag on a tall mast.

The cathedral was conceived by Bishop de Sully, who claimed he had seen the building in a vision. More pragmatically, Sully needed a cathedral in Paris so that he could compete with Abbot Suger's phenomenal cathedral in St-Denis, just north of the city. An army of stonemasons, carpenters, and sculptors came to work and live on the site, which had already seen a Roman temple, an early Christian basilica, and a Romanesque church. The chancel and altar were consecrated in 1182, but the magnificent sculptures surrounding the main doors were not put into position until 1240. The north tower was finished 10 years later. If both towers seem to some a bit top-heavy, that's because two needlelike spires were originally conceived to top them but were never built. The tower on the left is a tiny bit wider than the one on the right.

Despite various changes in the 17th century, the cathedral remained substantially unaltered until the French Revolution, when it was transformed into a Temple of Reason -- busts of Voltaire and Rousseau replaced those of saints. The statues of the kings of Israel were hacked down by the mob because they were thought to represent the despised royal line of France. An interesting postscript to this destruction occurred in 1977, when some of the heads of these statues were discovered buried beneath a bank on boulevard Haussmann. An ardent royalist had once owned that land; he salvaged the broken heads and buried them in his garden. The heads are now displayed in the Musée National du Moyen-Age.

By the early 19th century the excesses of the Revolution were over, but the reconsecrated cathedral was in dreadful condition. Napoléon crowned himself emperor here, seizing the crown from the pope and placing it on his own head in December 1804. (See David's epic painting of the lavish ceremony in the Louvre.) It was only after the publication of Victor Hugo's immensely popular novel featuring the hunchback Quasimodo that Parisians took notice of the cathedral's shabby condition. Architect Viollet-le-Duc began a renovation project that lasted through much of the 19th century. The spire is his invention; at the same time, Haussmann demolished the warren of little buildings in front of the cathedral, creating place du Parvis.

The facade divides neatly into three levels. On the first-floor level are the three main entrances: the Portal of the Virgin, on the left; the Portal of the Last Judgment, in the center; and the Portal of St. Anne (the oldest of the three), on the right. All are surmounted by magnificent carvings -- most of them 19th-century copies of the originals -- of figures, foliage, and biblical scenes. Above these are the restored statues of the kings of Israel, the Galerie des Rois. Above the gallery is the great rose window, and above that, the Galerie, at the base of the towers. The south tower houses the bell of Notre-Dame, as tolled by Quasimodo. Take a cue from Victor Hugo and climb all the way up the 387 steps of the tower (through the separate entrance, which is to the left of the facade as you face it). You'll be rewarded with the classic view of Paris, unforgettably framed by stone gargoyles designed by Viollet-le-Duc. To the north is Montmartre; to the west, the Arc de Triomphe, at the head of the Champs-Élysées; to the south, the towers of St-Sulpice and the Panthéon.

As you enter the nave, the faith of the early builders permeates all. The quiet, persuasive interior contrasts gracefully with the triumphant glory of the exterior, with the soft glow of the stained-glass windows replacing the statues of saints, virgins, prophets, and apostles. The best time to visit is early in the morning, when the cathedral is at its brightest and least crowded. At the entrance are the massive 12th-century columns supporting the twin towers. Look down the nave to the transepts -- the arms of the church -- where, at the south (right) entrance to the chancel, you'll glimpse the haunting 12th-century statue of Notre-Dame de Paris, Our Lady of Paris. The chancel itself owes parts of its decoration to a vow taken by Louis XIII in 1638. Still without an heir after 23 years of marriage, he promised to dedicate the entire country to the Virgin Mary if his queen produced a son. When this apparently miraculous event came to pass, Louis set about redecorating the chancel and choir. On the south side of the chancel is the Trésor (treasury), with a collection of garments, reliquaries, and silver- and gold plate.

Under the square in front of the cathedral is the Crypte Archéologique, Notre-Dame's archaeological museum. It contains remains of previous churches on the site, scale models charting the district's development, and relics and artifacts dating from the Parisii, who lived here 2,000 years ago, unearthed during excavations in the 1960s. The foundations of the 3rd-century Gallo-Roman rampart and of the 6th-century Merovingian church can also be seen.

If your interest in the cathedral is not yet sated, duck into the Musée de Notre-Dame (10 rue du Cloître-Notre-Dame), across the street opposite the north door. The museum's paintings, engravings, medallions, and other objects and documents chart the history of the cathedral. COST: Cathedral free, towers EUR6.10, crypt EUR3.30, treasury EUR2.50, museum EUR2.50. Métro: Cité.