Target Practice

Bombing targets are located throughout the country, on lands closed to public access, though the group of targets operated by the Navy in the Imperial Valley, at the southeastern corner of California, are unique in a number of respects, most noticeably their even, circular form.
Via The Center for Land Use Interpretation

Of course, sometimes the targets happen to be heavily populated areas as Issara reminds us by sharing a series of excellent photographs taken by her grandfather. A great document.