The villa of the Quintilii stands on a promontory generated by the lava flow from the Alban hills, between the via Appia Antica and the via Appia Nuova (ancient via Latina), looking out over the valley of the Statuario torrent to the north-east. Its particular position, which made its fortune, also facilitated the robbing of its sculptures and precious decor from the medieval period onwards. Further damage was caused by “official” excavations undertaken between the mid 18th century and the beginning of the 1900s, in order to enlarge papal and private collections (the Torlonia collection). Following its acquisition by the state in 1985, three excavation campaigns undertaken by the Rome Superintendency have revealed the planimetry only in the central zone of the complex, which extended over an area of circa 3.5 hectares. The earliest nucleus, built in _opus mixtum_ with facing in _opus reticulatum_, small tufa blocks and basalt chips with brick toothing, dated to the Trajanic-Hadrianic period. The subsequent phase, built in large basalt chips and brick courses, dates to the full Hadrianic period. Both were partially incorporated into the structures of the great nyphaeum on the Appia Antica, of the aqueduct, of the private residence and reception area, to which the great porticoed exedra was recently added. This structure provided the link between the entrance from the Appia Antica and the receptions rooms. It also gave access to the circular summer _triclinium_, companion to the octagonal winter _triclinium_, and lead to the splendid rooms arranged around them, decorated with mosaic and _opus sectile_ floors. The lead pipes found by Antonio Nibby in the baths area in 1828, bore the names of the brothers of Greek origins Condianus Maximus and Sestus Quintilius Valerius Maximus, members of one of the most influential senatorial families of the period. Both were consuls in 151 A.D. and they were known for their culture, military skills, their riches and brotherly love. In the Antonine period substantial building work was undertaken in the area of the _tepidarium_. The literary sources tell us that, in 182 A.D., the emperor Commodus (161-192 A.D.) had the brothers and the son of one of them killed. Officially, they were accused of having plotted against the emperor with his sister Lucilla, an accusation almost certainly made with the aim of confiscating their enormous property. This phase is attested by the “COMMODI” stamp impressed in the mortar make up for the laying of a pipe, found in the private baths, and the brick stamps in the sewers of the tambour of the so-called “maritime theatre”. The latter is now interpreted as intended to be a ludus in the Commodian plan, which was later changed during its construction into a _viridarium_ or ornamental garden, situated near the porticoed gardens. The creation of the _xystus_ in _opus listatum_, between the large nyphaeum and the reception area, dates to this period. Brick stamps found in the highest parts of the walls of the _frigidarium_ and _calidarium_ attest that these structures were enlarged during the Severan period. This phase also saw variations in the passageways through the villa, indicating changes in use. Other phases date to the end of the 4th century A.D., attested, among other things, by the presence of a glass kiln in one of the corridors in the reception structure, that had fallen into disuse. In the medieval period the castrum was built inside the large nymphaeum and a lime kiln occupied a small room in the _tepidarium_. The most interesting of the recent finds and statues from the early excavations are now displayed in an antiquarium set up in an old animal stall, close to the casale housing the office of the S.S.B.A.R. (entrance on the via Appia Nuova 1092). The recently acquired archaeological area of S. Maria Nova on the Appia Antica will soon be opened to the public. This site lies within the same territory as the villa dei Quintilii and it was here that the famous mosaic of the gladiator Montanus was found.