License, verbatimPD
The National Gallery of Art: open access image with no usage restrictions under the NGA's open access policy (openaccess=1 in the Gallery's published_images dataset).
Louis-Joseph Le Lorrain. The Seconda Macchina for the Chinea of 1745: Triumphal Arch for the Return of King Charles of Bourbon to Naples, 1745. National Gallery of Art, Washington.