The function of this Hadrianic building (opus mixtum and latericium, c. 125-126 AD), that has been called a warehouse, is not clear. Perhaps it was a market. On the side of Via della Foce is a porticus, behind which are four large shops. In the centre of the building are two large staircases. To the south of these are halls, to the north are rooms on either side of a barrel-vaulted corridor. The rooms in the northern part receive light through slit-windows in the back walls. Apart from the shops the building is aligned with the Tiber.

For decades people have not been allowed to enter the building, which threatens to collapse. The north part of the building has not been excavated.