There remain only the fine Early English choir, with Decorated additions, the Norman south transept and the majestic Decorated tower; while slight fragments of a Norman nave are seen.
In the south transept of the church is the tomb of the founder; the figure of Galeazzo guarded by angels lies under a marble canopy, with the Madonna in a niche above.
A curious two-storeyed building which adjoins the north transept consists of a chapel with a piscina below and a priest's chamber above.
The original edifice is believed to have been erected in the time of Columba, but the transept and nave of the existing structure date from the early part of the 13th century, the choir from the 15th.
Exquisite ornament is seen in the triforium arcade, and between some of the arches in the transept are figures, especially finely carved, though much mutilated, known as the censing angels.
The large bronze candelabrum in the left transept is said to be 13th century work.
Its cathedral of St Pierre, in some respects the most daring achievement of Gothic architecture, consists only of a transept and choir with apse and seven apse-chapels.
In a chapel in the south transept are the effigies of Henry II.
The chief building in Agen is the cathedral of St Caprais, the most interesting portion of which is the apse of the 12th century with its three apse-chapels; the transept dates from the 12th and 13th centuries, the nave from the 14th to the 16th centuries; the tower flanking the south facade is modern.
On the east side stands the two-aisled chapter-house (5), between which and the south transept is a small sacristy (3), and on the other side two small apartments, one of which was probably the parlour (6).