License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Stefano della Bella. The pyramid of Caius Cestius at right in the background, a horse grazing at center, a foal suckling a mare at left, two shepherds at right, plate 11 from "Roman landscapes and ruins" (Paysages et ruines de Rome), ca. 1646. The Metropolitan Museum of Art.