With its two facing apses, each with a chancel, and the absence of a main doorway, Cathédrale St Jean (12C) is undeniably original. The astronomical clock is a masterpiece: made up of 30 000 parts (19C), it was designed by Auguste Lucien Vérité. Near the large organ is the famous painting by Fra Bartolomeo, Madonna in Glory with Saints. Until the French Revolution, the eastern apse housed a holy shroud that is considered to be as authentic as the Turin Shroud.