Ntang Dreaming, 1989, by Aboriginal Australian artist Emily Kame Kngwarreye. More of the artist's work is available via her curated collection tour at the National Gallery of Australia and her collection at the Art Gallery of New South Wales.
Image from the book Astronomy for Amateurs, written by Nicolas Camille Flammarion and Frances Alice Welby and published 1904. Image scanned by The Internet Archive and uploaded to their Flickr as a part of the Internet Archive Book Images collection. In case the Internet Archive is down at the time of reading, Astronomy for Amateurs is also available from the Wikimedia Commons.
Example of a stone sphere from the pre-Columbian Diquís people of what is now modern-day Costa Rica, currently in the collection of the Metropolitan Museum of Art. Additional pieces by the Diquís can be found in their Met collection and on the Wikimedia Commons. This particular image, as with all Diquís artifacts in their collection, is in the public domain per the Met's Open Access policies. (Wikimedia images vary in permissions, but are typically under Creative Commons licenses by the creators.)
