License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Giovanni Battista Piranesi. Remains of a covered portico, or a cryptoportiucus, in a villa of Domitian, five miles outside Rome on the Frascati road, from Vedute di Roma (Roman Views), ca. 1766. The Metropolitan Museum of Art.