Open Collections | OpenGLAM
"Here we list openly licensed datasets from several cultural institutions. All collections provide digital scans or photos that can be freely used without any restrictions. Most of the objects are in the Public Domain because of their age, or are licensed under an open Creative Commons license (CC-BY/CC-BY-SA). This is an ever expanding list so if you know of datasets that are not listed here, get in touch. Please also let us know if you have published, remixed or re-used the data in any way..."