One of the great Cathedrals of Europe is Chartres Cathedral in France. Construction of the cathedral began in 1194 after a fire destroyed the existing structure. Chartres is a wonderful example of gothic architecture, boasting the largest collection of Medieval stained glass in the world. The huge windows displaying these works of art are made possible by the flying buttresses, which support the walls of the cathedral. Chartres is also a marvel of engineering, as witnessed in this brief video.