Las Médulas were the most important gold mines of all Roman empire. They were explored from 19 B.C. until mid-3rd century.
"Mons Medullius", also the site of asturian battles.
Now the remaining land, richly forested, offers a strange scenery of beauty, history and geology. That´s why it is classified by UNESCO as one of the nature's wonders of Spain.
The Asturian territory was known by the romans for its soil, rich in metals like iron, tin and gold. Pliny, who visited the region for some years, wrote:
"The mountains of Hispania, barren and sterile, and producing nothing else worthy, had at least to produce gold"
The gold fever, that opened around 50 exploitation sites, may have been caused by the introduction of the gold coin the aureus, part of an impostant monetary reform by imperor Augustus.
Pliny estimates a "6 500 Kg per year" production of gold; that would be 6 to 7% of the roman annual erary income! The profits were certainly more modest, as according to modern research gold was only around 1 gram per cubic meter, with scarce bigger nuggets - Pliny refering palagas of more than 3 Kg !!
Pliny described the mining technique:
"This type of mine has been given the name of Ruina Montium. The cracks made in the entrails of the stone are so dangerous that it would be easier to find purpurine or pearls at the bottom of the sea than make scars in the rock.""Broken, the mountain falls in on itself with a noise louder and a wind more violent than any human mind could imagine…"
Oaks, chestnut trees, willows, alders, cork trees, and vigorous heather ( up to 2m high), form a dense and varied grove.
The capricious forms of the ruined mounts interact with the bush and forest, creating an uncommon landscape, with the rosy peaks emerging from the green canopies.