In the last years of the 2nd century AD or the beginnings of the 3rd century, the Las Médulas mine – like all the gold mines in the peninsular north-west – ceased being exploited. The explanation for this is to be found in the close relationship between the gold mining operations and the Roman monetary system.

Augustus standardised the monetary system in line with a bimetallic standard based on gold coins (aureii) and silver coins (denarii). This reform is a fundamental factor for understanding gold mining during the Roman Empire, as its production was State controlled and aimed, to a great extent, at minting coins. The relevance of gold in minting money explains why the monetary crises of the 3rd century AD had such a direct influence on the end of mine working in places such as Las Médulas. Since then no gold has been extracted from it.

As the ancient mining industry was never resumed, the vestiges of Roman mining in Las Médulas are enveloped in a halo of mystery and legend, the fruit of the ignorance of realities the historical memory of which had fallen into deep obscurity.

One of the main representatives of the subsequent development in the area is the Castillo de Cornatel (Cornatel Castle), set on a high mountain in the old Ourense road. This was a stronghold essential for the district; its history is linked to important members of the León nobility and afterwards with the Templars. Evidence of the importance of the monasteries in this area is the neighbouring Cistercian monastery of Santa María de Carracedo, of key significance in the works of Gil y Carrasco and recently restored by the Diputación de León (provincial council).