St Agnes's bones rest in the church of her name outside the old walls of Rome (hence, Sant'Agnese fuori le mura, "Saint Agnes outside the walls"). The current church, as rebuilt by Pope Honorius? in the mid-7th century, stands over a 4th century catacomb? or underground cemetary. In the fourth century the soft rock had been hollowed out around St. Agnes's tomb to create a gathering space, probably for her family to observe the anniversary of her death. The visits of her family and friends spread early to others in Rome, and the site became a place of pilgrimage. By the end of the 4th century the Constantina, daughter of emperor Constantine, had enlarged the underground area and built a church over it. The floor level of the 7th century church is at the level of the catacomb floor, and street entrances are at the level of the 2nd floor gallery.
A later church was built after 1652 on the site of her martyrdom (hence, Sant'Agnese in Agone, "Saint Agnes in Agony") in the Circus of Domitian, now the Piazza Navona, by the important Baroque? architect Francesco Borromini.
At Sant'Agnese fuori le mura on her festival (21st of January) two lambs are specially blessed by the pope after a pontifical high mass, and their wool is later woven into pallia, ceremonial neck-stoles sent by the popes to newly elevated archbishops to symbolize their union with the papacy.