The Church of St. Jerome and the Certosa Cemetery are located in an area where an ancient (5th century BC) necropolis of Felsina (Bologna) was situated, the remains of which were discovered during 19th century archaeological digs.
The Church of St. Jerome is accessed from the east side of the cemetery entrance courtyard. The current layout, in inverted T form, is the result of 16th century extensions that added to the original 14th century church a two-aisle transept developed on the facade side, therefore placed in reverse with respect to the norm. The nave, formed of two aisles and square apses, is covered in ribbed vaults and separated by sharp arches embellished with 15th century decorations. The 16th century chapels of St. Bruno and St. Jerome are in the transept to the right and left.
The construction of three chapels placed along the north side, outside the church, probably dates back to the first half of the 15th century: the Chapel of St. Anthony the Abbot and later of St. Joseph, the Chapel of St. Bernardine or Our Lady of the Annunciation, and the Chapel of the Relics. They form a single body with the building, with shared exterior details and the same type of covering. A fourth chapel used as a sacristy was added after the inauguration of the church.
The medieval facade, in bare brickwork and next to the small 14th century bell tower, is crowned with a pattern of terracotta trefoil arches on hanging columns; large round windows replace the original single windows. This is partially hidden by the loggia circumscribing the entrance courtyard. This was extended in 1768 with the monumental entrance of five Tuscan arches, the work of architect Gian Giacomo Dotti and the last major architectural work to be carried out. Also from the 18th century are the twenty-three arches of the west portico (interrupted before the church entrance) and the first thirteen arches of the east portico, while the rest of the loggia is what remains of the 15th century cloister.
The large bell tower of the church was built by architect Tommaso Martelli in 1611 for the Carthusian fathers to supplement the small 14th century bell tower which no longer sufficed. Around fifty metres high with a square base and exposed brickwork curtain wall, the bell tower is divided into four levels separated by string courses. On the lower level, with wide corner pilasters, are rectangular windows on two sides; on the other three floors are large round blind arches with twin Doric, Ionic and composite pilasters on the first and second floors, while on the third are mullioned windows of 15th century tradition with freestone columns and circular oculi in the tympani. The tower is crowned with a composite cornice surmounted by a balustrade and pairs of pinnacles at the level of the pilasters, on which the pyramid of the spire is set.