Not far from the Catacombs of Saints Marcellino and Pietro, there is the Mausoleum of St. Elena. It is a monumental tomb of Roman placed along the Via Casilina, corresponding to the third mile of the ancient Via Labicana. The Mausoleum is accessed by Via Casilina input adjacent to the church of Saints Marcellino and Pietro at Ad Duas Lauros.
The majestic tomb was built by the Emperor Constantine I between 326 and 330 A.D.. Originally the building was intended for Constantine himself, it would have been his monumental tomb. Later, however, it was used as a tomb for Elena, the mother of the Emperor, who died in 328. The Mausoleum of St. Elena, as it was later called, is an imposing building. The lower cylinder has an outer diameter of 27 meters. Originally, the total height was of 25 meters, today it is about 18 meters high. It featured a domed roof, probably decorated with mosaics. At the top of the dome, between the drum and the vault, huge pots were inserted to lighten the weight of the structure and prevent its collapse. Fragments of pots are still visible on the site. Their presence and their clear visibility has produced a neologism among the population of the district. In fact people used to name the Mausoleum "the tower with the pots”. Nowadays, the area is known as Torpignattara (the tower with the pots). In 1632, a small church was built inside the Mausoleum. It was dedicated to Saints Marcellino and Pietro. In the XVIII century the building was enlarged.
Inside the Mausoleum there is a multipurpose museum able to revive the traveler-faithful the majestic past of the Mausoleum and of the entire archaeological site.