Amiens Cathedral, upper nave, north

The upper nave of the cathedral seen from the north side. You can also see one of the west towers and a bit of the north transept. Note how the exterior buttresses have been brought up to form supports (culées) for diagonally-placed stone props that support the weight of the upper nave with its masonry vaults. These are "flying buttresses" (arcs boutants) that allowed the builders to create such tall, slender, light-filled stuctures. The first flying buttresses had been deployed some eighty years earlier and builders learned how to exploit them to achieve cathedrals that were ever taller. Amiens at 43.3 meters is a little lower than Beauvais at 46m. The upper nave was built by Master Thomas de Cormont in the 1230s.