The interior consists of a dark, barrel-vaulted nave with no clerestory, narrower side aisles, a transept crossing topped with a tower, a small choir, and a groin-vaulted ambulatory with radiating chapels. A faded 12th-century fresco survives on the choir vault. The rest of the murals, which cover the nave columns and other surfaces with garish geometrical designs, date from the 19th century. There is only one narrative capital, which depicts the Ascension of Christ with angels.