… and there, where human greed once tore apart the bowels of the earth, today stands an almost unreal landscape, defiant, enigmatic and attractive, where the clamour of a centuries-old silence paints in the air the frenzy of those who sculpted a territory pregnant with riches with which to feed the glory of Rome.
‘The earth is carried away by the rivers and the women, after kneading it, wash it in basket-shaped sieves to extract the gold.’ This is how the Greek geographer Posidonius describes the technique used by the aureanas, gold prospectors who populated the banks of the rivers of north-western Iberia in the 1st century BC. Testimonies of this nature and the discovery of pre-Roman objects, crafted by skilled goldsmiths, clearly demonstrate that the Asturian tribes who inhabited this corner of El Bierzo were already exploiting the gold deposits before the arrival of Rome.
Who were these ancient inhabitants of the land that today offers us such beauty? Here, it is necessary to quote the writings of Estrabón, as his meticulousness in compiling information on the way of life of the subjugated peoples constitutes an inexhaustible documentary source, leaving us with such interesting accounts as this: “All the inhabitants of the mountains are sober, drink only water, sleep on the ground and wear their hair long in the feminine style, but in war they tie it up with a ribbon or turban. They sacrifice goats, horses and captives to the god Ares. They practise physical exercises, wrestling, running and mock battles in line. For three quarters of the year, they feed only on acorns and chestnuts, which are dried, crushed and ground into flour. They drink zythos, a drink derived from the fermentation of grains, due to the scarcity of wine, which, when obtained, is quickly consumed at large family feasts.
The men wear black robes and cloaks in which they wrap themselves to sleep on their straw beds. The women wear dresses with floral decorations. Internally, instead of currency, they practise the exchange of goods or precious metals…”
Parricides are stoned to death outside the villages, and other criminals are thrown from high cliffs… Originally, they used inflated hides to cross rivers and lakes, but after Brutus’ Roman expedition, they began to use boats made from hollowed-out tree trunks… They are very warlike peoples with harsh and primitive customs, mainly due to their isolation, as the routes to reach them are long and arduous…
However, despite being considered barbarian peoples, it is no less true that Roman historians gave them the status of a people due to their clear social structure. This same order determined the urban layout of the settlements, whose designs followed the guidelines of the Castreña culture of the Northwest. The centre is ‘el castro’, that is, a fortified hamlet built in a dominant topographical position from which the surrounding territory can be visually controlled. Within the walls, dwellings were built with local stone and vegetable roofing, inside which domestic activities and the specialised family economy took place.
The arrival of Rome
By the middle of the 1st century BC, after two centuries of occupation of the Iberian Peninsula, the north-western quadrant remained un-Romanised. These were the lands of Asturias, with their rugged terrain and extreme climate, whose inhabitants were considered aggressive and violent enemies, according to historians of the time.
The constant skirmishes that had been taking place since the middle of the previous century had already brought the new inhabitants of Hispania into contact with the northernmost tribes, but it was not until 29 BC that the Roman military machine began to operate intensively. It was Emperor Augustus’ determination not to leave any uncivilised areas in the imperial lands and the interest aroused by the riches of the subsoil, according to the Roman historian Florus, “… the nature of the country favoured this plan, as the entire region contained abundant gold, borax, minium and other products”, which triggered the start of forceful military campaigns that would not end until 19 BC with the total subjugation of the north-western tip of the peninsula.
At the head of the army that subjugated the Asturian people was General Carisio, who first defeated them in the city of Lancia, very close to the present-day city of León, and then went on to fight what would be the decisive battle of Mons Medullius, which some historians place somewhere near Las Médulas. Once again, the Roman historians Florus and Orosius, acting as notaries of their time, describe how the Asturians, in order to avoid becoming slaves, ended the conflict: ‘…in the midst of a feast, they killed themselves with fire, the sword and the poison extracted from the yew trees here.’
A country turned into a quarry
This is how Rome’s hand turned a libertarian territory, whose bowels were an immense gold vein, into part of a province oligarchically subject to the established power, from which it extracted enormous quantities of the precious metal.
‘Augustus ordered the land to be exploited. Thus, working painstakingly underground, the Asturians began to discover their own riches while searching for them for others,’ as Floro described what happened at the end of the war.
Romanisation and the exploitation of gold mines under a state monopoly led not only to the transformation of the landscape, but also to a social, economic and technological revolution. Notable cities such as León and Astorga were founded, which Pliny the Elder would describe as ‘urbs magnifica’ when they became the administrative capital of the north-western mining basins and the starting point for important roads along which gold would be exported to the main cities and ports of the Peninsula.
The permanent presence of a large military contingent in the area not only guaranteed security but also provided technical support in the construction of infrastructure such as the canals that brought water from long distances. Mining and metallurgical settlements were built to supply the needs of the exploitation, and human settlements were promoted in the existing castros. New methods of agricultural and manufacturing production were imported. In short, this meant a complex change in customs and a modernisation of the Asturians’ way of life, leaving behind the subsistence economy, self-sufficiency and, in some respects, primitivism.
Several settlements of different chronologies and functions have been identified in the Las Médulas area, which structured this mining metropolis over time. A clear example of an Asturian-type settlement is El Castrelín de San Juan de Paluezas, whose circular huts, protected by a wall, often feature craft workshops that show the life of pre-Roman peoples before industrial activity, or the castro of Borrenes, whose construction was influenced and halted by the emergence of Roman power.
The Roman settlement of Orellán provides us with a picture of the specialisation that was characteristic of the Empire, as the dwellings, which were already quadrangular in shape and distributed according to an orthogonal urban layout, were accompanied by smelting furnaces for the manufacture of iron tools. This reflects a model of exploitation that is complemented by the Las Pedreiras site, a stately residence attributed to one of the administrators of the mining complex, which boasted the distinctive luxuries of a Roman mansion: rooms arranged around a peristyle or porticoed courtyard, stuccoed and polychrome walls, etc.
Far from attempting to give history lessons, I consider this journey through time to be interesting in order to fully understand the context and reasons that gave rise to Las Médulas, that cultural and environmental treasure, a World Heritage Site and unique in Europe, which last summer’s fire managed to destroy. Thus, travellers who visit the site will feel privileged to walk in the footsteps of the Romans who, with wisdom and ambition, squeezed many millions of cubic metres of red earth to extract almost all the gold it contained. They left behind a landscape that was devastated but generous, rugged but fertile, and with an innate beauty that transcends far beyond mankind and its history.
The Ruina Montium sculptor of Las Médulas
‘…caves are made over long distances, they dig into the mountains with oil lamps, and these lamps themselves are the measure of their work and vigils, and in many cases they do not see daylight.’ “…the heads of the arches open and split, signalling ruin. And only those who are vigilant on the heights of the mountain know this. With their voices and blows, they command the workers to quickly move away…‘ ’…once broken, the mountain falls by itself, with such a great roar and wind that it cannot be conceived by the human mind…‘
This is how the Roman geographer and naturalist Pliny the Elder describes the gold extraction process in some deposits in the Astur territory in his work Naturalis Historia, reaching its peak in Las Médulas. This technique consisted of manually excavating a complex network of wells and galleries into which large quantities of water were suddenly released. Due to erosion and the water hammer effect, this caused a large part of the mountain to collapse.
On the contrary, when the drilling reached a core of solid rock, other procedures were necessary, such as applying fire and vinegar to break it up, which produced dense smoke and steam that suffocated the miners. To avoid this, iron sledgehammers weighing almost fifty kilograms were used to remove the small fragments manually, passing them from hand to hand day and night.
At the same time, alluvial deposits were exploited using a process known as ‘arrugia’, which involved the construction of large water reservoirs at higher levels than the vein, from which a series of channels carried the water needed to wash the earth down to the washing areas in the lower areas.
Once the mountain had been demolished and the rocks separated, the mud was channelled into small ponds, which today appear as beautiful spots such as the evocative Somido Lake near Las Médulas or the generous Carucedo Lake. The pits were built in the form of terraces covered with rough bushes to retain the coveted metal. Once the bushes were dry, they were burned, and the ashes were then washed to separate the gold.
Another curious example, due to its rarity, is the La Palombeira cave. Located a short distance from the centre of Las Médulas, but part of the same mining complex, it is a long gallery that in some places reaches more than thirty metres in height, excavated in slate stone. Initially, it was thought that it might be a drainage tunnel, but more recent studies have confirmed that it is a gold mine, without ruling out the possibility of other minerals given the diverse characteristics of the rocks.
It is particularly difficult to calculate how much profit Rome made from the El Bierzo basin, the most important in history, as the most recent studies do not provide a clear figure. Once again, Pliny the Elder estimated production at 20,000 pounds, or about 6,540 kilograms per year, which would represent around seven per cent of the total revenue of the Roman treasury.
But none of this would have been possible without the use of enormous amounts of labour. Although native slaves were initially used, they were later replaced by legally free men who were forced to work without pay or maintenance as payment for the tribute accrued for the preservation of their land rights.
Such was the degree of human exploitation that Silio, another author of the time, referred to the miners as ‘pallidus’ because of the colour of their skin, which was in constant contact with the reddish earth. This coincides with Floro’s assessment of the Asturians, whom he describes as ‘more yellow than the metal they seek’.
Gold ingots from El Bierzo continued to arrive in Rome until the 3rd century AD, when the mines in the north-west began to close. The economic crisis that was ravaging the already declining Empire and the abandonment of the precious metal as the official currency standard meant that mining activity was irreversibly abandoned, leaving future generations with an unprecedented historical and landscape legacy.
Without question, Las Médulas is the universal benchmark for Roman mining activity. In the words of writer Enrique Gil y Carrasco, it is a landscape ‘of a strange and fantastic appearance due to the deep gashes and ravines of red clay…’. This gigantic feat of Roman engineering is now a fairy tale from which stories and legends of gold prospectors spring forth. From the Orellán viewpoint, on the dizzying edge of a 100-metre-high ravine, the spectacle is of a beauty that is difficult to describe, while from the Pedrizas or Medulillas de Yeres viewpoints, you can appreciate the magnitude of the work now that we know a little more about its origin.
In the background, the great circus with its floor carpeted by thousands of chestnut trees, many of them centuries old and survivors of the last fire, supports an army of suggestive reddish peaks of capricious shapes, giving volume to the vanishing point that leads us to the village of Las Médulas, a small, typical village in El Bierzo from which you can start an attractive tour of the bottom of the site by following the circular Vallinas trail. In the distance, lost in the distance, lie the plains where the washing places were once located and where today the charming Lake Somido is found, and at the bottom of the valley, the enormous Lake Carucedo, source of a thousand and one legends.
Near the Orellán viewpoint, a path descends to the village through centuries-old chestnut trees and farmland, where it is easy to lose yourself in the wake of the pinnacles that bear witness to the height of the mountain before mining activity. At the end of the route, it is impossible not to gasp in admiration when you reach the mine entrances of La Cuevona and La Cueva Encantada, where, according to legend, the witch who guards the mountain’s treasure lives. Their height of almost twenty metres gives us a real idea of the work of water in wearing away the tunnels and causing the “ruina montium”.
From both the Orellan viewpoint and the village of Las Médulas, following the Camino Real, you can start a tour along the perimeter path of the mine, which takes you to Campo de Braña, where the aqueducts arrived and where several sections of canals are preserved, continuing on to Las Medulillas de Yeres and its spectacular panoramic view of the rest of Las Médulas. For the more energetic, after a climb of just over 900 metres, the Reirigo viewpoint is a must-see for its wonderful views of the site in all its splendour and of the Aquilianos mountains, which provided so much water for gold extraction.
The hiking route is dotted with very interesting features such as the Mediterranean forest that surrounds it with a rich botanical variety of holm oaks, chestnut trees, cork oaks, strawberry trees, gall oaks and Pyrenean oaks, as well as the traces of mining represented by the enormous accumulations of stones, known as murias, and the galleries visible on many slopes.
Without the channels, Las Médulas would not exist
The implementation of all this infrastructure required considerable prior investment. Water, an essential element for the use of these forms of exploitation, was not always available. Pliny the Elder mentioned above recounts that ‘there is another task that is even more costly, and that is to bring rivers from the tops of the mountains to wash away this debris, sometimes from a hundred miles away.’
To alleviate the problem of the constant water supply that the farm needed, the Romans carried out an unprecedented hydraulic project in this territory, even going so far as to carry out the first water transfer in history between two river basins: the Duero and the Sil.
A comprehensive network of canals and aqueducts was constructed, enabling water to be collected from snowfields, springs and streams, sometimes at altitudes of nearly two thousand metres.
This same technique was used to capture water at the headwaters of the Eria River, part of the Duero basin, and deliver it to the Cabo River, whose waters flow into the Sil, both in the El Bierzo region.
In total, around a thousand kilometres of channels were built to guarantee the constant flow of tens of millions of cubic metres of water needed to maintain mining activity. These channels run along the slopes of the Aquilianos mountains, around Las Médulas and along the western side of the Teleno mountain range, but all with the same purpose: to supply water to the gold deposit. There are currently more than one hundred kilometres of marked trails that run through different channels, the main one being the GR-292, a long route that connects Campo de Braña, next to Las Médulas, with the town of Llamas de Cabrera on the slopes of Pico de la Cruz. Along the way, there are different variants that invite you to discover other points of interest in this complex hydrological network, as is the case with the rest of the kilometres of canals that form the backbone of this corner of the El Bierzo region.
Another interesting and recently refurbished spot is the bed of the Roman canal in Yeres, which can be accessed at a junction on the perimeter path very close to the start of the climb to the Reirigo viewpoint. Along its 500-metre length, you can see the mathematical layout of the canal to avoid the slopes, as well as some cuts in the rock where you can see the water level. And if we are lucky, we may be surprised by the company of some of the forest’s inhabitants.
Some of the scenes described in this report suffered the cruel ravages of fire in the summer of 2025, but the charm and cultural value of Las Médulas remain unchanged, so some photographs may differ slightly from the current reality. Fortunately, recent studies carried out by technicians from the Higher Centre for Scientific Research (CESIC) have determined that the damage is not irreversible and that, with a little help from man and the action of nature itself, this historical landmark will soon be restored to its former glory. But that doesn’t mean we should stop visiting and enjoying it.
