Astronauts from ISS Expedition 41 photographed 12 miles of the Iraq-Iran border, near the Persian Gulf coast, on Nov. 7, 2014, using a Nikon D4 digital camera using an 800 millimeter lens.

"Systems of large curved earthworks, circular gun emplacements, and straight connecting roads run parallel to the international border," wrote NASA's Earth Observatory, which is located in the Goddard Space Flight Center.

"First thought by the ISS team to be oil-pad installations, the strategic location of these formations along the international boundary made it easier to see these as patterns of military fortifications," it continued. "This region of oil refining and exporting was the center of numerous military actions during the war in the 1980s, especially during the defense of the southern city of Basra."