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).
Joseph Vigier. Saint-Sauveur. Sentier du chaos conduisant à Gavarnie (Saint-Sauveur. The Path to Chaos Leading to Gavarnie), 1853. National Gallery of Art, Washington.