License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Sangallo family. Recto: The Houses of the Barbarians (Vitruvius, Book 2, Chapter 1, nos. 3, 4); Verso: The Aeropagus in Athens with Cave Houses (Vitruvius, Book 2, Chapter 1, no. 5)., 1530–45. The Metropolitan Museum of Art.