Communities from Colombia have been credited with creating a vast irrigation network thousands of years ago that researchers describe as an engineering marvel. A new study found the pre-Hispanic field systems of La Mojana, which covered around 500,000 hectares, were likely built through cooperation between local communities rather than under the control of powerful rulers. The network of canals and raised fields helped manage floods and droughts for centuries. Researchers say the sustainable approach could offer lessons for modern-day Colombia as it faces growing water management challenges.