The catacomb is found in a rural location (called “St. Hilary”) at the 30^th mile of the ancient Via Latina not far from the present-day centers of Colleferro and Valmontone. The cemetery is made up of a good number of galleries and cubicula that have given back epigraphic and ceramic materials (found today at the City Antiquarium of Colleferro).

In front of the catacomb an important open-pit cemetery lies that is delimited by a fence which preserves many tombs in masonry or excavated in the rock (fourth-fifth century).

On this funeral area, at the end of the eighth century, a small church stood (precisely the church of St. Hilary), which represents one of the best preserved examples of high medieval buildings for worship in Latium.