Retelling an 800-year-old story, Chartres, France. A train trip of 55 miles from Paris brought me to Chartres, the best preserved medieval cathedral that exists.

Inside this magnificent structure I met Malcolm Miller, almost as much of an institution as the cathedral he adores. Since 1956 he has been studying and lecturing about the building, decoding the stories written in glass and stone for thousands of visitors, scholars and tourists alike.

Miller literally wrote the definitive book on this place, titled (imaginatively enough) Chartres Cathedral.