Las Médulas is a historic gold-mining site located in the province of León, Spain. It was designated a UNESCO World Heritage site in 1997, and is one of the most important examples of Roman mining engineering in the world.

The Romans began mining gold in the area around Las Médulas in the 1st century AD, and the site was in use for more than 250 years. The mining method used by the Romans was called "ruina montium," which involved diverting rivers and creating channels to wash away the soil and expose the gold deposits underneath.

Over time, the mining activity at Las Médulas drastically altered the landscape, creating a series of terraces and canyons that are now known for their unique red and orange colors. The site is now a popular tourist destination, with many visitors coming to explore the ancient mining tunnels, hike the surrounding hills, and take in the stunning scenery.

In addition to the mining activity, Las Médulas was also an important agricultural center during the Roman era, and the area is home to several well-preserved Roman villas and farmhouses. Visitors can explore these ancient structures and learn more about daily life in the region during the height of the Roman Empire.