The past isn’t even past, and it’s still quite explosive:
Luftbilddatenbank, based on the top floor of Carls’ home just outside Würzburg in the southern state of Bavaria, specializes in finding bombs using old aerial photos. In the last five years, the company has digitized hundreds of thousands of images, developing a database of geographical coordinates and archival reference points that let them request photos of specific locations from collections of wartime photos in Washington, DC, and Edinburgh, Scotland.
Followup to this, and h/t to Jonathan Beard.
The Edge of the American West 
2 comments
April 10, 2012 at 6:10 am
Main Street Muse
The “iron harvest” offers random yields as well. A WWII-era bomb was found in Chicago not long ago. http://bit.ly/HwC2Xp
April 10, 2012 at 12:42 pm
JWL
In the Cornelius Ryan book A Bridge Too Far are clearly delineated aerial photos of the outlines of U.S. gliders, taken decades after 1944, which had burned into the heaths of Holland. If memory serves, they can’t be discerned at ground level.