This giant basilica consecrated in 1253 marks the Franciscan movement led by Brother Elius towards architectural splendour and decoration. It consists of a sober and bulky inferior Basilica decorated with frescoes (by Simone Martini) and a tall and slender superior basilica which is a really accomplished piece of Gothic architecture for you to see, decorated with an admirable cycle of paintings by Giotto. Unfortunately, the 1997 earthquake seriously damaged these paintings.