The church, also dedicated to St. James, has a single longitudinal nave covered by a three-span cross vault also visible in the extrados. The end of the nave is closed by an apse as wide as the nave itself and lit by a window with three lights. The frescoes along the walls and on the vault were painted in 1690, as is shown by the date on the internal architrave of the entrance portal.

The largest and best conserved fresco in the church is found inside on the entrance wall. The original 14th c. rose window above the portal was covered in order for the fresco to be painted but was discovered during restoration work carried out by Chierici in 1929. Though it was opened on the outside, the rose window was left closed on the inside in order to conserve the fresco in testimony of the various historical vicissitudes the Certosa has experienced.  [ More...]