Before going into the cathedral, however, the traveller lingers before the façade, the west front, which is the best-known front, and the one through which you enter, since the other two are inaccessible, the north front because of the cloister and the south front because of the beautiful railing that surrounds the cathedral, isolating it from the street. The west front, which includes the twin yet assymetrical (one is taller than the other) towers, is formed by a fine gable with a rose window and four other windows (eurythmic, the books call them), and, below, at ground level, the best part of the front: the triple porch with its Gothic sculptures, called the Porch of the White Virgin.
With nobody to interrupt him, he can linger as he pleases in nave, aisles and chapels, stopping every so often to admire the windows: that series of glass pictures that fill the building (hence the impression it gives of fragility) and that constitute one of the loveliest collections of its kind in the world.
Fifty-seven bullseye windows or oculi, three enormous rose windows, more than a hundred and twenty-five other windows... The profusion of glass is so fabulous (one thousand eight hundred square metres, the traveller reads in his guide books) that he does not know what to look at, or from where to get the best view of this infinite play of figures and colours that covers the whole fabric, from the west front to the apse. The impression it gives is of being in a dream [...]: nearly a quarter of its structure is glass, which makes it even more graceful and delicate.