This building has been dated to the Trajanic period (opus mixtum). Various modifications can be seen. It consists for the most part of a large hall. Some piers indicate that at least part of it had a roof. In the south-east part is a row of small rooms, accessible from the street, apparently small shops. In the room in the south corner is a wall-niche for statuettes of deities. To the north of the row is a wide entrance from the street. There is a further room in the north corner, with a basin to the east and a staircase to the north.

The building seems to have been used for commercial purposes, like the adjacent hall 7. This district, outside the Marine Gate, had a very specific nature. Two honorary funerary monuments were built here. Near the beach were the large Baths of the Marine Gate. On the spot of the later Building with Opus Sectile were a dike and a mole. Buildings 6 and 7 must somehow have fitted into the character of the neighbourhood. Perhaps the hall in building 6 was used as a stable by people who spent a day on the beach and in the baths.