Droughts act as time machines by revealing lost ancient cities

Archaeologists call these rare events 'drought windows,' brief moments when the receding waters of reservoirs and rivers act as a physical rewind button on the landscape. In Spain and Germany, the foundations of ancient stone circles and villages were often left intact because they were too heavy to move when 20th-century dams were built. When water levels plummet, these heavy relics emerge from the silt perfectly preserved, offering a fleeting look at a map that was supposed to be lost forever.