From Rod Dreher's The Little Way of Ruthie Leming:

On the way to Paris from London, the coach stopped in a town around sixty miles southwest of the French capital. Our group was going to see a famous Gothic church, they told us. Fine by me. By then I had shed the small-town faith in which I had been raised. Being a seventeen-year-old man of the world, I was fairly confident that God did not exist, but I was pleased, of course, to look at beautiful churches. 

This is the untutored boy from the sticks who ambled unaware into Chartres Cathedral, one of the great architectural treasures of Western civilization. The complexity, the beauty, the sheer genius of the thing staggered me. I moved past the huge statues of biblical patriarchs, carved into the jamb of the west portal door, and into the narthex, staring gape-mouthed at the soaring arches in the church vault. Who had built this? How had they done it? And in the thirteenth century! It looked like those thin ribs held aloft tons of limestone, and, miraculously, those vast stained-glass windows, great sheets of reds, greens, blues, and golds, glowing in the sunlight like rubies, emeralds, and sapphires in the firmament, forming portraits of Jesus, His mother, the prophets, and the saints. Nothing in my experience had prepared me for the glory of this building, and the overwhelming scale and intensity of its beauty. 

I walked out of that cathedral a different man, though I wouldn't understand what Chartres had done for me until years later . . . The bus drove on to Paris, but I recall not one thing about the first time I saw the Eiffel Tower, ate a real French baguette, or much else about my maiden voyage to this city that figured so prominently in my boyhood imagination. I only remember Chartres. It was, to me, a message from another time and place, and a mystery. I did not know what it said, not yet, but I wanted to find out. What kind of religious vision can inspire men to build a temple like that to their God? What is God saying about Himself through the stone and the glass of that cathedral? What is he saying to me?

To be sure I did not become more religiously observant on that trip, or back home for my senior year of high school. What happened was that Chartres put me onto something. I was still a teenage boy full of himself and longing to drink beer and chase girls, but in Chartres I had encountered something that for all its stony mass and solidity, seemed to me a thin veil over a higher reality. It sounds strange but I felt . . . judged by Chartres. I had seen it; I couldn't unsee it. Chartres haunted me, principally because having been there, I could no longer say with any conviction that Christianity was nothing more than middle-class social conformity or a con game for nitwit followers of TV evangelists.