A new Tumblr site by the National Geographic showcasing rare photos, most of which have never been published. Check out the About page, where you can see William Bonner, Guardian of the Collection and Curator of the Photography Archive, in action — no doubt picking out a rare image to be posted.
And the captions are just as great as the captures. Like this one: “A cowgirl puts a nickel in an El Paso parking meter to hitch her pony, October 1939.”