Every year some 12 million visitors, watched silently by a menagerie of Gothic gargoyles, chimeras and grotesques, teem through the portals of Notre Dame de Paris.
Some, of course, come to pray. Most come to take photographs, bathe in the plays of kaleidoscopic light through great rose windows, stare into the high pointed vaults, listen for bells and, perhaps, sense something of the mysterious, miraculous and even diabolical.
In the popular imagination, Notre Dame has long been the most gothic of Gothic churches.
And, yet we owe much of its theatricality to Victor Hugo, whose 1831 novel was set in the magnificent cathedral. English speakers know it as The Hunchback of Notre Dame.
Hugo wrote it to draw attention to the sorry state of the cathedral. Much damaged by passionate zealots of the French Revolution, when for a spell it had been rededicated to the Cult of Reason and then to the Cult of the Supreme Being, it was also, despite classical intrusions complete with cherubs playing in plaster clouds, notoriously Gothic and, therefore, dark, dismal and out of fashion.
Hugo's novel sparked intense new interest. A competition held in 1844 to renovate the cathedral was won by Jean-Baptiste-Antoine Lassus and the young Eugène Viollet-le-Duc, a passionate Gothic revivalist. The cathedral was revived with structural repairs, bestiaries of new sculpture and the spire we saw flaming like a gothic torch today.
When, after 25 years, the architects' work was complete, Notre Dame was deeply and movingly Gothic even though much of it was new. For all its venerable vaults, stained glass and flying-buttresses, the cathedral we know and love is as much a 19th century as a medieval creation.
Spared serious damage in World War II, cleaned and renovated in 1963, from 1991 and again in recent months, Notre Dame has not been allowed to decline again. But fire, however caused, has no respect for sentiment and much less for timber beams under high roofs, whether 19th century or medieval.
Sentiment, however, will see Notre Dame rise from the flames, not miraculously but by determined effort and through the deep pockets of the state. The big question for the future is how will the clergy, architects, experts, officials and the French public itself wish to see Notre Dame restored?
Little more than 80km from the Île de la Cité, the new restoration of Chartres cathedral, Notre Dame's contemporary, has prompted both gothic horror and angelic delight.
A sublime whole built mostly between 1194 and 1230, the stones of Chartres matured more subtly than the noblest French wines. The patina of centuries was painterly and poetic. All those generations of hands and bodies, tapers and candles, incense and dust.
From 2009 the Monuments Historiques decided a wash, brush-up and makeover was needed. The garish effect of stained glass in brightly painted and gilded new walls, Adrien Goetz has written in Le Figaro, is like "watching a film in a theatre where they haven't turned off the lights".
With luck, and prayers, Notre Dame may escape Chartres' ritzy fate. Or maybe Paris needs a new Victor Hugo to champion the spirit and charred and splintered fabric of this towered, spired and gargoyled gothic survivor.
- Jonathan Glancey is an architecture critic and writer