The façade, in late Romanesque style, is divided into three compartments by full height pillars. Its characteristic, uneven gables break up the roof line. The entrance of the building consists of a large wooden double door, topped by a plastered rounded arch. Above the door is a three-light window with rounded arches. Two other single windows, equal to the previous ones, are centered at the front of the aisles. At the left of the church there is the entrance door to the bell tower. The bell tower is made up of four stories, marked by four projecting cornices. The right and left sides of the church coincide with other buildings, with shared walls. On the outside, the choir presents a row of three single arched windows.
The central nave is separated from the side naves by four pillars with rectangular bases and six pointed arches. The right aisle, at the second bay, has a large niche with altar. The left aisle, at the first bay, near the entrance, has a niche that corresponds with the central span, third span, and two other niches.
The Presbytery is accessed on the left by three marble steps, and the opening leads into the sacristy. The Chorus, on the right and left, has semicircular niches. On the right side, an opening leads to the garden of the church. The apse has an upper triple lancet window.
The building dates from the eleventh-twelfth century. It overlooks the main square of the historic center of Bagnaria, near the ruins of the castle. The building was thoroughly studied by experts during restoration work in 1946, after serious damage was caused by an earthquake. The various engineers and art historians, studying the church, testified that it was built from 1050 to 1100 in the Romanesque style. The damaged, peeling of the plaster on the walls allowed the experts to examine the exposed sandstone walls underneath. This also allowed for the verification of a trussed ceiling, with parts of it, still in good condition. Both brackets that supported the cross-beams, were still in place for the beams of the trusses to rest on.
By removing the plaster from the walls, pictures of the Saints have been discovered, as well as, the residue of other decorations. On the right wall of the baptismal font, the figure of St. Carlo Borrome was uncovered, though very deteriorated. Above the second pillar, on the left when you enter the Church, the figure of St. Alberto, was discovered. On other parts of the walls, there were relics of figures in fresco that could not be identified. Unfortunately, none of these images could be saved. The moisture in the lime and another layer of color and plaster totally compromised the images.
Though no one knows why, the architects and other experts of ancient art, made the decision to replace the mid-1600s ceiling trusses, with brick masonry. The brick was also applied to the pavilion vaults, the cruise, and to the central part of the pillars themselves. The primitive style was therefore tampered with. To accomplish this work, much of the artistic decoration done in a previous times was also destroyed. As it can be seen with certainty, the primitive building, which was originally done in stone, had a new form of artistic exterior which was added in 1500, decorating all the walls with many figures in fresco, as it was a popular decorative form, in use at that time.
Certainly, during this period, the Church must have been seen in all of its majesty and glory. Though it is sad that as previously stated, around the middle of the 17th century, in order to make the outer layer of lime (plaster) stick to the existing walls, the original images were ruined on every wall.
When the time came to install the trusses, for unknown reasons, not being able to do so, the Civil Engineers decided to build a wooden coffered ceiling (also the engineer Cinnarelli had planned to build the coffered ceiling in wood). This work began on February 25, 1946.
The decoration of the whole interior of the church, the figures of the saints and the decoration of the facade of the church with the bell tower was painted by Mr. Domenico Fossati, assisted by his nephew Alessandro Silla, both from Tortona ... "(News from the book: ROLANDO SAPELLI, Bagnaria. history men and facts, Guardamagna Publisher, Varzi, 1997). Imperial decree on the vestry of the church, 1809 AP Bagnaria, Cards 5. Account book of the Venerable Parish Factory Bagnaria, 1810 (excerpt plan of the church and the bell tower) The date of construction of the bell tower is taken from, 1871 AP Bagnaria, Cards 9. Documentation relating to the restoration, in 1939 c. AP Bagnaria, Cards 23. Report on the conditions of stability of the church of Bagnaria in 1929 AP Bagnaria, Cards 28. Projects for the accommodation of the presbytery with drawings (1979-1980-81) AP Bagnaria, Cards 30.
Rectangular, with three naves (three bays to the nave). Semicircular apse; bell tower on the left side, is in line with the facade.
Gable roof; covered with brick tiles.
TIMES OR GARRET
Nave: Wooden coffered ceiling, richly decorated. Aisles: Wood paneled ceilings angled at 45°.
Staircase to access the building.
External facing; dark red plaster on which is engraved a plot of brick walls arranged in a cross. The lack of some sections of plaster in the lower part of the façade highlights the technique adopted; brick masonry (with cross-bedding) and mortar.
Source: Thesaurus montanus. I Beni Architettonici e Artistici della Comunità Montana Oltrepo Pavese, book and CD-ROM, ed. Torchio de’ Ricci, Certosa di Pavia, 2003