The pre-Hispanic field systems of La Mojana in the Colombian Caribbean are so vast that they can be seen from a plane at high altitude. Their canals and raised fields—in use from the first centuries B.C. until the 11th century A.D.—cover an astonishing 500,000 hectares (1.2 million acres), roughly the same size as Grand Canyon National Park or three times the size of London.

It has traditionally been assumed that powerful rulers must have ordered and managed such an ambitious infrastructure project because of its complexity and the amount of work thought to be involved.

In a study published in Communications Sustainability, however, a University of Cambridge-led archaeological team argues that the work was most likely locally led, cooperative and much faster than previously assumed.

The findings are historically important but also offer hope to Colombians today who are suffering from a water management crisis linked to climate change, intensive farming and policy failure.