Stock images database

[WalterRobin]

Endless database of Earth images under Creative Commons:
http://loworbittourist.tumblr.com/

[WalterRobin]

http://www.openculture.com/2016/04/download-67000-historic-maps-in-high-resolution-from-the-wonderful-david-rumsey-map-collection.html

[margocargo]

https://www.jpl.nasa.gov/spaceimages/?search=&category=Earth#submit
apparently the collection of Nasa Jet Propulsion Lab is also under Creative Commons