J Paul getty museum

https://www.getty.edu/

https://www.getty.edu/about/whatwedo/opencontent.html

The Getty Museum maintains a large collection, about 100,00, images available in the public domain, including ” paintings, drawings, manuscripts, photographs, antiquities, sculpture, decorative arts, artists’ sketchbooks, watercolors, rare prints from the 16th through the 18th century, and 19th-century architectural drawings of cultural landmarks.” The images are from around the world and include Edward S. Curtis photographs of indigenous Americans, European illuminated manuscripts, sculpture from 4th century BCE Japan, and Egyptian coins. Unfortunately, downloading the images from their site proved difficult.