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. Profile of the Temple of Fortuna Virilis (Profilo del Tempio della Fortuna Virile), and section of the temple, from "Le Antichità Romane", 1756. The Metropolitan Museum of Art.