The Porticus of the Republican Monument is located to the south of the Decumanus Maximus, near the theatre. Behind the porticus is a row of four shops, behind which is a large hall. The building was named after the republican funerary monument V,XI,6 at the east end. It was built during the reign of Commodus (opus latericium).

A corridor to the east of the shops leads to a wedge-shaped, Hadrianic warehouse. At the north end is a large hall with two rows of brick piers. Later many rooms were created in the hall. To the south is an open area with some 100 buried storage jars, dolia defossa, that contained olive oil or wine. The word annona has been applied to the building, so the food supply of Rome organized by the Emperor. The size of the building suggests that the oil or wine was not for local use, but meant for Rome.

The southern part, with a staircase and some piers, has not yet been excavated completely.