The city of Ur, located in modern-day Iraq, might at some points have covered more than eight times as much ground as previously estimated.

Pictures taken by a cold war spy jet and satellites show that the Mesopotamian city of Ur sprawled over a much bigger area than scientists had realized.

As a city-state and the seat of an embryonic empire, Ur was an important urban centre from 3800 to 500 BC, a status reflected in the sumptuous treasures buried in its Royal Cemetery during the third millennium BC. Yet scholars estimated that the city, located in what is now Iraq, covered only 60 hectares — making it much smaller than other Mesopotamian cities.

To revisit that estimate, Emily Hammer at the University of Pennsylvania in Philadelphia pored over declassified images captured during the cold war by US spy satellites and a U-2 spy plane. Hammer also surveyed the area around the sites detailed in the photos.

She found that at some points in its history, Ur might have occupied roughly 500 hectares — which is more than 80% larger than medieval London. At that size, it would have been one of the largest Mesopotamian cities of its time.