The west part of this building was erected c. 150 AD, the east half (hatched) in the third quarter of the second century. The masonry is opus mixtum, in the west half consisting of reticulate framed by bricks, in the east half of reticulate framed by opus vittatum. The same masonry was used for the facade, which is unusual: in this period facades are usually of brick only.

The building is made up of shops along Via della Caupona, and of rooms on three sides of a long, rectangular courtyard (16). The shops have entrances that are not very wide: 1.20-2.00 m. The street and the courtyard are connected by an entrance corridor (5) flanked by a staircase (4). The rooms around the courtyard have narrow doors. In the courtyard is a large basin. Room 21 has been identified as a latrine. On photos taken during the excavation of this building, of building IV,II,4, and of the courtyard of the House of Hercules, large heaps of fragments of marble slabs can be seen, while large heaps of mosaic tesserae are documented in this building and the neighbouring Inn of the Peacock. Apparently material for re-use was being collected here, probably in the fourth or early fifth century.

It is not clear for what purpose the ground floor was used. Perhaps the curious nymphaeum-like structure in room 12 provides a clue. It is a free standing structure in the rear part of the room. It consists of a podium with a small wall on the back part. In this wall are holes for water-pipes. In the podium is a hole running from the top of the podium to the front, diagonally downwards. The room does not have any doors. In front of the south-west wall is a low wall, creating a narrow compartment. In the south-east wall is a window, in the south-west wall a wide opening, perhaps also a window. It is as if the entire room was flooded.