For over seventy years, people have been driving out in their RVs to a remote desert area near the city of Yuma, in the US state of Arizona, to write their names and leave messages on the desert floor. Unlike regular graffiti that is hurtful to the environment, at Valley of Names messages are spelled out by carefully arranging rocks and small boulders in the hard-packed white sand.

The practice probably began during the Second World War when U.S. Army General George Patton brought his soldiers to this flat rocky area to train. This training camp, known as the Desert Training Center, was the largest military training ground in the history of military maneuvers. The camp grounds stretched from the outskirts of Pomona, California to within 50 miles of Phoenix, Arizona, and from the suburbs of Yuma to the southern tip of Nevada.

Photo credit: Bob Bales/Flickr