Amiens Cathedral, Nave, interior north aisle looking east

We have just entered by the saints' portal and find ourselves directly in the brightly-lit space of the nave. We are looking straight down the north aisle: in the distance you can see the space of the north transept and beyond that the choir aisle.
As originally built, the nave aisles would have been vastly different: on your left you would see the shimmering colored glass of enormous windows entirely filling the space of each bay above a lower wall articulated with a little arcade or dado. All this changed when lateral chapels were added between the 1290s and 1370s: the original windows were knocked out and the dado of the lower wall removed and reused in the new outer wall.
The space of the aisle is determined by three squares one atop the other: it is the same proportion as the main vessel. The bays of the aisle are covered by quadripartite rib vaults: the plan of each vault is very close to a square. To the right you can see the elegant supports of the main arcade. Each support is composed of a central cylindrical unit flanked by four smaller shafts (or colonnettes) placed in the north-south-east-west axes. These units, known as piliers cantonnés can also be found at Chartres, Reims and Beauvais Cathedrals.