he construction of the Saint-Nazaire-Saint-Celse Cathedral dates back to June 12 1096, when Pope Urban II,. blessed the stones on the site. It is a cruciform church with a wide Roman nave whose barrel vault is supported by two side aisles with roman arches. the apse which was destroyed during the Gothic reconstruction, probably had two apsidioles (small apses) on the axis of the side aisles. The entrance to the cathedral is from the north into the third bay of the nave. It consists of a porch decorated with sculptures set beneath solid concentric arches which jut out slightly from the facade.