Creative Commons had an announcement on their website that,
CC Search comes out of beta, with over 300 million images indexed from multiple collections, a major redesign, and faster, more relevant search … CC Search searches images across 19 collections pulled from open APIs and the Common Crawldataset, including cultural works from museums (the Metropolitan Museum of Art, Cleveland Museum of Art), graphic designs and art works (Behance, DeviantArt), photos from Flickr, and an initial set of CC0 3D designs from Thingiverse.
Photo Credit: “On The Way” by Beryl_snw is licensed under CC CC0 1.0