The Mausoleum of emperor Maxentius was part of a larger complex on the ancient Appian Way (Via Appia) in Rome, which included a residential imperial palace and a chariot racing circus, Circo di Massenzio, constructed by the Roman Emperor Maxentius.

The large circular tomb was commissioned for construction by Maxentius in the early fourth century CE, probably as a dynastic or family tomb starting with himself, but when his young son Valerius Romulus died in 309 CE, before the emperor himself, he was buried there, hence the name Mausoleum of Romulus.

circa 312 CE

Exterior
The mausoleum is a massive circular structure with a diameter of approximately 32 meters (105 feet). It originally had a conical roof, but this has not survived. The exterior is adorned with engaged columns and sculptures. The entrance, an arched portal, to the tomb was most likely marked by a grand archway adorned with sculptures. The mausoleum or tomb of Maxentius is believed to have been originally a two-story building. The core of the structure composed of a cylindrical rotunda with a diameter of approximately 35 metres, but today only its semi-underground floor survives. The brick-martar staructue of the circular tomb is partially buried below the modern ground level in the surrounding area of the mausoleum.

circa 312 CE

Interior
There is a central octagonal pillar with a diameter of some nine meters and this pillar is encircled by a seven meters wide, vaulted corridor with open niches where the sarcophagi were placed during antiquity. No trace has survived of floor or wall decorations, suggesting that the building may never have been completed.

circa 312 CE

Quadriporticus
The circular tomb was enclosed inside a perimeter wall and a quadriporticus, which isolated it the mausoleum from the rest of the suburban imperial estate. The enclosure walls and parts of the quadriportico have survived to some height on the north, west and the east sides. These remains survive up to the height where the springing arches for the cross-vaults would have. This cross-vaulted passageway that originally ran along the entire interior perimeter of the quadriporticus is thought to have been used for the funerary processions or circumambulation rituals in the ancient times. The walls of the quadriportico were constructe in the opus vittatum style.

circa 312 CE

Eighteenth Century CE Farmhouse
An eighteenth century CE farmstead, which was later converted in to a larger farmhouse, largely obscures the mausoleum from the ancient Appian Way (Via Appia Antica) and stands where a columnar porch once framed the tomb's principal entrance. This farmhouse and was later converted into a proper home by the Torlonia family, who owned it until it was taken over by the Fascist government (Comune di Roma) in 1943 CE.