The different parts of the complex include: The church of the Crucifix is of Lombard origin and dates back to the 8th century: it consists of a single nave with a trussed vault and a raised presbytery on the crypt.
Under the presbytery there is the crypt divided into five naves with columns of different invoice, one of which, according to legend, from the base to the capital is perfectly equivalent to Jesus (about one meter and seventy, very high for the time); at the end of it, in two urns placed on an altar, the remains of the Saints Vitale and Agricola are kept.
In ancient times it was possible to crawl inside to venerate the remains of the saint; the prostitutes of Bologna, on Easter morning, moreover, in memory of Mary Magdalene, went there to pronounce, before the Holy Sepulcher, a prayer whose content they themselves never wanted to reveal.
Today the body of St. Petronius is no longer in this church, after which in the year 2000 Cardinal Giacomo Biffi had it moved to the Basilica of San Petronio, which already guarded the head of the patron saint of the city.
In 393 the remains were moved from Ambrogio to be taken to Milan (a fact that testifies that the basilica was already built) and also in the fifth century a messenger was sent by Namazio, bishop of Clermont, to get relics of the Bolognese protomartyrs.
The courtyard is bordered to the north and south by two porticoes in Romanesque style with characteristic cruciform columns in brick and brings to the center a limestone basin resting on a 16th century pedestal.
Under the portico, in the center of a window, on a column, there is a stone rooster dating back to the fourteenth century, called "Gallo di S. Pietro" to remember the evangelical episode of the denial of Jesus.
Significant for the symbolism of the passion of Christ is that the distance between this courtyard and the nearby church of San Giovanni in Monte (so called because it stands on the only natural protuberance of the central dish of Bologna) would be the same that there is in Jerusalem between the Holy Sepulcher and Calvary.
A detailed study of the work published in 1981 by Massimo Ferretti, at the end of the first major restoration carried out by Marisa and Otello Caprara, has identified the sculptor of the statues as the Master of the Crucifix 1291 kept in the Art Collections of the City of Bologna.
The work remained colorless until 1370, when it was commissioned by the Bolognese painter Simone dei Crocifissi who took care of the rich polychrome and gilding with his very personal Gothic style.
Finally, on 21 January 2007 the complete work was inaugurated inside a large electronically controlled humidity and temperature case, equipped with shatterproof glass, which now houses the entire group permanently.
In this church there are also pieces of frescoes from the 14th century, in particular a fragment showing Sant'Orsola with her companions of martyrdom and a pregnant Madonna who, besides being of exquisite workmanship, touches the loving gesture with which she caresses her bursting belly; the other hand of the Virgin holds a book.
The focus of scholarly discussion has been for many years the supposed similarity between the so-called "New Jerusalem" rebuilt here, according to a vita written in 1180, by Saint Petronius in the 5th century, and the largely lost 4th-century complex erected by Constantine the Great at the purported site of the crucifixion and resurrection of Jesus.