St Mary's features a Romanesque narthex, a Gothic nave and St Bertrand's mausoleum. The cathedral according to Flaubert: "An immense boxwood jube is the entire church, it overlooks the chancel and the nave, the priest and worshippers. Does it not have a bit of everything - Antiquity in the Romanesque, the 16th century in the 11th, the Renaissance in the Middle Ages?"
This mix of different periods can be better seen in the village. In fact, Saint-Bertrand-de-Comminges, a Romanesque church surrounded by fields, seems to have incorporated numerous elements from older religious places of worship to its construction and decor - for example, a Paleo-Christian column capital was used as a holy water font.