[2] The main organ built by Stoltz featured in the Universal Exposition of 1855 in Paris,[3] according to legend, offered by the Empress Eugénie in 1858 to the cathedral of Agen that hitherto had no instrument.

It is a nationally listed historical monument and so too is the choir organ built by the makers Magen in 1885, with 15 registers, two manuals and a pedal-board.

Interesting architectural features include the Romanesque apse which is extended by a Gothic frame along a single nave.

Other paintings are by series: the Evangelists, the Apostles, the patriarchs (Abraham, Noah ...) and the great kings of Israel.

The cathedral's nave is much shorter than might be expected judging from the size of the chancel: this was the consequence of earlier political and financial difficulties.