I sometimes complain that the people of my country pay far too little attention to the glories of their own land and culture. They slog for thousands of miles on planes to view the Taj Mahal or the Temples of Angkor Wat, but it never crosses their minds to visit the Cathedrals of Durham or Lincoln. They bore you to death about the beauties of the French countryside, and they have never visited the Malvern Hills or the North York Moors.

But here I make a wider criticism of the modern world. The modest French city of Chartres can be reached in a day from London, by train. The Eurostar will take you to the Gare du Nord, and then a direct journey on the Paris Metro (Direction Porte Bagneux) will rattle you over to the Gare Montparnasse, where reasonably frequent trains leave for Chartres, an hour away. On the way, especially if your train is a double decker and you ride upstairs, you get rather a good view of the great palace of Versailles. Yet I suspect most inhabitants of this country, or visitors to France, will never visit it. This is their loss.

The Cathedral at Chartres is not just one of the greatest monuments to human thought and skill and faith in France, or in Europe, but in the world. Yet it is not really announced as such. It is surrounded, in winter at least, by a quiet, modest and not especially prosperous town. Not far from it, in rather drab surroundings, stands the haunting, almost desolate, freezing cold church of Saint Pierre which in any other place would be famous for its astonishing stained glass, but because of its nearby competitor, is comparatively neglected. It was so empty and seemingly forgotten when I visited it that it brought to mind the M.R. James ghost story "Canon Alberic’s Scrapbook," set in and around the echoing, shadowy, mysterious church of Saint Bertrand de Comminges (a real place close to the Pyrenees). Fortunately for me, I did not find in Chartres what Monty James’s hero found in Saint Bertrand.

What I did find (for I had been there before long ago, callow and rushed, and had not really taken it in) was so much concentrated thought, wisdom, and glory that I had to take rests between visits because my eyes and brain became too full to take in any more.

I had, with rare foresight, remembered to take binoculars with me. These are, if not essential, very helpful in studying the stained glass windows which have, astonishingly, survived Reformation, revolution, and war. Chartres is unique in many ways. It was built with incredible speed, an extraordinary act of worship by nobleman and peasant side by side, carting the stones to the site. Designated as a shrine to the Virgin Mary herself (and probably owing something to long-buried pagan worship on the same site centuries before), it was never used for the burial of the dead. It is one of the earliest examples of the great achievement of late Gothic architecture, the flying buttress, by which our supposedly ignorant and stupid forebears solved the complex problems of supporting high walls and a great roof, while also having enormous windows through which the light could pour.

In these days of pre-stressed concrete, we are used to such things (though most concrete buildings are ugly because their strength is used to defy the law of gravity rather than to employ it as an ally). But in the thirteenth century, those benighted, superstition-ridden simpletons, our forebears, constructed a building four hundred thirty feet long, one hundred fifty feet wide, and one hundred twenty-one feet high, with two great towers capped with spires (one three hundred forty-four feet high, the other three hundred seventy feet high). And it was so strong that they were able to pierce its walls with one hundred seventy-six windows.

Many of these windows are so lovely, and so full of delicious detail, that you could easily spend hours studying them. My favorite illustrates the Parable of the Prodigal Son which (as I explain in my book The Rage Against God) has always had a special resonance for me. But it is only one among many, whose colors, detail, serenity and—oh, what is it?—grace, peace, truth, all combine to compel the mind into thought.

Then there are the sculptures—not only the sombre, mysterious saints and kings and prophets on the porches, but many others, some unknown, and reminiscent, in their power and majesty, of the tremendous statues in the cathedral at Naumburg near Weimar in Germany. Job is depicted on a dunghill, in a portrayal of his extreme misery which is quite hard to look at because it is so graphic and unsparing. I did not have enough hours to examine all the detail in these, though I had a pretty good look at the great carved choir screen, which (being devoted to the Virgin) contains stories from the Golden Legend now more or less forgotten in Protestant England. Nothing like this has survived in Britain, and one has to wonder at the resolve of the Chartres citizens who managed to prevent the wrecking of this place during the Jacobin frenzy of 1789 and afterwards, when French churches were converted into Temples of Reason, and prostitutes were encouraged to climb on to their desecrated altars.

The sculpted part of Chartres is, as someone else has said, something like a mediaeval Acropolis. And, for those who enjoy dismissing religion as backward and opposed to science, logic, and reason, please note that among the figures lovingly portrayed on the great west front are Euclid and Pythagoras. These bumpkins were not bumpkins. These backward people were not backward people. These dark ages were suffused with light, and light filtered through the windows of Christian teaching (the sight of the entire building illuminated through its great west windows at sunset is one I shall not easily forget).

What Chartres represents is a map and model of the cosmos (something similar can be said about Jan Van Eyck’s otherwise inexplicably fascinating triptych The Mystic Lamb in the cathedral at Ghent) enabling anyone with eyes to see to find an explanation of the spirit which motivates the universe, which arranges the stars and the comets in their orbits and courses, and which also causes our consciences to burn within us, and our eyes and ears to recognize truth and beauty when we see them. It is not literal, and not for the literal-minded. But then again, nor are poetry or music. And it is almost a cliché to say that Chartres is poetry and music, frozen into stone and glass.

As I studied this great possession of our civilization, I was reading (for I had been asked to review it) yet another anti-God book penned by a clever man of our age. I felt that this building was and always would be a sufficient answer to his case. Man gropes, in all ages, for an understanding of where and what he is, and what he should be and do. It seems to me that he will find, in Chartres, a more useful guide than he will find in the Charter of Human Rights, or in the other unimaginative, cold, dry attempts to construct justice and liberty without understanding where these ideas come from in the first place.

I am not a Roman Catholic, and did not attend Mass in the Cathedral. Instead, I slipped into the crypt on a windy night to hear Vespers (similar to the English Evensong) sung. Fortunately, my French is bad, or no doubt I should otherwise have disliked the modern language in which psalms, Bible, and canticles were (rather beautifully) sung. As it was, I could imagine that it was the equivalent of Coverdale’s golden trumpets "My soul doth magnify the Lord, and my spirit hath rejoiced in God my saviour . . ."

In a moment of complete silence, the wind could be heard sighing through the spires and towers high above. Nothing else could be heard to disturb thought. We were doing what had been done, more or less without a break, since the beginning, centuries before, and what (it is reasonable to hope) may still be going on centuries from now.

The modern city outside, of car parks, cafes, cinemas and pedestrian precincts was, by contrast, a thing that would be gone quite soon. The time would rapidly come when, seen in faded photographs or worn out film, the Chartres of today would look quaint and long ago, its people oddly clothed and comical. What would abide would be the great mysterious church, filled with disturbing proclamations of seemingly absurd propositions, like a great rock in a river, with ordinary time rushing past it on either side.

This post originally appeared in the Mail on Sunday under the headline "What Will Survive of Us? The Miracle of Chartres Cathedral." It is reprinted here with the author's permission.