Crystal Mill, one of the most-photographed (though most difficult to reach) historic sites in Colorado.
It sits in what is now mostly a ghost town, whose few residents leave the area in the brutal winters of the High Rockies. The settlement is reachable by a four-wheel-drive vehicle along a narrow, rock-strewn road that hugs a frightening precipice. Original image from Carol M. Highsmith’s America, Library of Congress collection. Digitally enhanced by rawpixel.