St Severin is the doyenne parish churches of left bank of the Seine. It is the most beautiful Parisian church in the blazing Gothic style. The history of this church starts at the 6th century with Severin, a very pious hermit who lived there. The small oratory which honoured Severin became a vault, then a basilica. After the destruction by the vikings the church was rebuilt and became a parish church during the 11th century. This church has the oldest triforium of Paris, a very beautiful déambulatoire composed of 10 double spans of pillar-palm trees.