We must remember that any sculpture less emphatic would have been ineffective, because practically invisible, in this sombre place. But at the west end there is an escape for the eye, for the soul, towards the unhindered, natural, afternoon sun; not however into the outer and open air, but through an arcade of three bold round arches, high above the great closed western doors, into a somewhat broader and loftier place than this, a reservoir of light, a veritable camera lucida. The light is that which lies below the vault and within the tribunes of the famous narthex (as they say), the vast fore-church or vestibule, into which the nave is prolonged. A remarkable feature of many Cluniac churches, the great western porch, on a scale which is approached in England only at Peterborough, is found also in some of the churches of the Cistercians. It is characteristic, in fact, rather of Burgundy than of either of those religious orders especially. [137] At Pontigny itself, for instance, there is a good one; and a very early one at Paray-le-Monial. Saint-Pere-sous-Vezelay, daughter of the great church, in the vale below, has a late Gothic example; Semur also, with fantastic lodges above it. The cathedral of Autun, a secular church in rivalry of the "religious," presents, by way of such western porch or vestibule, two entire bays of the nave, unglazed, with the vast western arch open to the air; the west front, with its rich portals, being thrown back into the depths of the great fore-church thus produced.