Archaeologists have used high-resolution satellite snapshots to finally piece together a mystery surrounding the ancient people of Peru’s famous Nasca region.

The mystery centres around a series of carefully built, spiralling holes called puquios, burrowed into the ground in the Nasca Desert of southern Peru. These peculiar formations could not be dated using traditional carbon dating techniques, and the Nasca people didn’t leave behind any evidence of when they were first established, so archaeologists have spent centuries trying to figure out their purpose in vain.

As BBC Future reports, this provides insight into how this network of tunnels and caves was created in Nasca. It’s now believed that the primary aim of the puquios were to enable communities to survive in an area continually hit by drought: they were essentially a cutting edge hydraulic system used to retrieve water from aquifers underground.

“What is clearly evident today is that the puquio system must have been much more […]