In the northwest of the Aquilanos Mountains and along the valley of the River Sil, is Las Médulas, an amazing landscape resulting from ancient Roman gold mining, and listed as a World Heritage Site by the UNESCO. This place presents an impressive reddish hue that draws a sinuous and enigmatic landscape. No one would imagine the hidden gold behind the steep cliffs that the Romans extracted centuries ago. Silenced for a long time, the mining exploitation of Las Médulas has become a fascinating tourist attraction, complemented by the museum infrastructure of an archeology classroom. Here is a detailed description of the time when the largest open-pit gold mining in the entire Roman Empire operated.