For decades, archaeologists suspected that a strange landscape hidden in the Spanish Pyrenees was more than a product of nature. Deep trenches, artificial ravines and enormous excavated areas hinted at a forgotten human story buried beneath the mountains. Now, researchers have confirmed that the site, known as Guilleteres d'All in northeastern Spain, was once a Roman gold mine nearly 2,000 years ago. The discovery of an ancient reservoir preserved beneath layers of sediment has provided the strongest evidence yet that Roman engineers used sophisticated hydraulic mining techniques to extract precious metals, reshaping an entire mountainside in the process and moving millions of tonnes of earth without modern machinery.
