This building measures c. 59 x 45 meters. It has been excavated only partly. It was built with opus reticulatum with a few bricks, dated to the middle of the first century AD. In the interior are rooms (7 x 4 meters) arranged around a courtyard. A curved wall in the north-west part has been dated to the fourth century (opus latericium).

The building was called a warehouse by the excavators solely because of the abbreviation HOR on two cippi on the road to the west, the Semita dei Cippi. There is little or nothing in the architecture to suggest storage. Recent geophysical research by Michael Heinzelmann suggests that the curved wall is part of the arena of a small amphitheatre that had been installed in the building. Nearby is a large concentration of basalt blocks, possibly a dump of the excavators.