Las Médulas

Las Médulas, in the Bierzo district of north-western Spain, looks like a natural wonder — jagged peaks and hollows of vivid orange-red earth rising from chestnut woods — but it is largely man-made. It is what remains of the largest open-cast gold mine in the Roman Empire, where engineers dismantled entire hillsides with water. UNESCO listed the cultural landscape in 1997, and the landscape it recognises includes not only the ravaged hills but the canals, reservoirs, settlements and spoil heaps that made the operation work.

The technique was called ruina montium, "the wrecking of mountains", and it was described by Pliny the Elder, who served as a procurator in the region in the 70s AD and may have seen it at work. Miners drove long galleries into the hill, then flooded them from reservoirs above until the pressure brought the whole slope down; the collapsed debris was washed through channels to separate the gold. To feed this, at least seven aqueducts tapped streams in the mountains of La Cabrera, some carried along precipitous rock faces. Pliny reckoned the region yielded 20,000 Roman pounds of gold a year, and large-scale extraction ran from the later first century AD for some two centuries. Lidar surveys in 2014 revealed that the works extended much further than had been thought.

The scale had consequences then and debates now. Greenland ice cores show a peak of atmospheric pollution in the Roman era that was not matched until the Industrial Revolution, and when the site was listed one committee delegate objected that it commemorated environmental destruction. Visitors today see something gentler: vegetation has reclaimed much of the ground, and walking trails wind between the pinnacles, while stretches of the aqueducts survive in precipitous places, some with inscriptions cut in the rock.

The best overview is from the Mirador de Orellán, a lookout on the rim above the village of Orellán, reached by a short walk from a car park; next to it the Orellán gallery lets visitors walk through an old Roman tunnel with a hard hat, though access has been interrupted for works. In the village of Las Médulas there is a visitor reception centre, and an archaeological classroom explains the mining system.

Getting there

Las Médulas lies about 17 km from Ponferrada; by car, head for Carucedo and follow local roads to Las Médulas village or Orellán. The nearest airport in a straight line, Bragança (BGC) in Portugal, is about 67 km away but has very limited service; León Airport (LEN), about 92 km away, is the nearest in Spain. A car is by far the easiest way to reach the site.