Pianta degli avanzi del Portico fabbricato da M. Emilio Lepido, e P. Emilio Paolo fuori della Porta Trigemina nell' Emporio alla ripa del Tevere [Plan of the remains of the arcade built by M. Aemilius Lepidus and P. Aemilius Paullus outside the Porta Trig

The Porticus Aemilia was probably a granary for storing grain offloaded from the wharves of the Tiber. First erected in 193 B.C. by the consuls Marcus Aemilius Lepidus and Lucius Aemilius Paullus, it was rebuilt in concrete, perhaps as early as 174 B.C. It may be the oldest surviving concrete structure in Rome. This print shows the plan (A), longitudinal section (B-C), cross section (D), and details of wall construction: regular tufa blocks (H), irregular tufa pieces (I, detail shown at L), and opus incertum (a concrete core with facings of irregular small stones set in mortar, M).