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"Las Médulas: World Heritage Site"

Ancla 51
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Download map of Las Médulas

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route map

Gold mining:

The archaeological park of Las Médulas is one of the most important mining remains from the Roman era. The ancient Medulios mountains, through Roman engineering and with the efforts of thousands of slaves and employees to obtain the precious golden metal, have become a unique landscape in an ancient area of Celtiberian forts that were later Romanized as the town of Pedreiras in Lake Carucedo or the metallurgical town of Orellán.

For topographic measurements they used the dioptrae, a tachymeter used to calculate distances and draw levels, aided by the chorobates, a type of square wooden ruler of about twenty feet (5,920mm). Other tools used were the punterola, the punt and the lamp.

The orography caused them great problems, they had to dig tunnels in the rock to transport water and they were also forced to demolish rocks. To demolish a rock, they heated it by burning large amounts of heather on its surface and then poured water mixed with salt and vinegar on top, causing the rock to explode and break apart.

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Hydraulic network and exploitation:

The extraction process used gave rise to various channels, which were used for the evacuation of waste, especially when the extraction was carried out at higher levels, as can be seen in the place called Lagua D'Eres.

The Las Médulas mine was built on an alluvial deposit (secondary), made up of silt, sand and boulders. It comes from other rock deposits (primary), carried and deposited by water currents during the Miocene, late Tertiary age.

The site was exploited since the end of the 1st century BC. until the end of the 2nd century AD. It is a huge site and had a considerable height. Due to the thickness of the alluvium, the Romans resorted to water to exploit the deposit. The Romans were exceptional engineers and had unrivaled power over water.

To obtain gold, they used about two million cubic meters of water per year. During the three hundred years that the exploitation lasted, it was possibly the largest hydraulic network in the Roman world, some three hundred and thirty kilometers of canals called corrugios, so called because they meandered the north and south slopes of the Aquiliano mountains to capture water. from the summits of the rivers, some more than two thousand meters high and about one hundred kilometers away.

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The agogae or laundries:

It is estimated that approximately 7 tons of gold were extracted. The necessary labor force is estimated at several thousand workers, the majority of them Asturian, both salaried and slaves, as well as African slaves.

In order to be able to move all that huge amount of forest and be able to eliminate the surface layer, they created eight canals to bring water from the Sil and Cabrera rivers. Thus, through reservoirs, with gates and secondary channels, they gradually demolished the mountain, washing it to obtain the precious gold. The gradient obtained in the canals did not exceed 0.5% per kilometer; The width of the channel was 90 to 150 cm and the height of the transported water was 10 to 20 cm.

The washing process was carried out on the plain, they dug trenches in the ground, through which the water flowed and at intervals they covered them with urces or heather; The sides of the ditches were covered with boards and if the terrain required it, aerial channels were used. The water left the gold ore in the vegetable filters. The process ended by drying and burning the heather, whose ashes were washed over a grassy grass bed so that the gold could be deposited.

Legend and reality:

Legend has it that in the town of Las Médulas it was the Asturian leader Médulo who from the top of the mountains faced the Roman legions, but their superiority ended with the native resistance, whose men preferred death by fire and poison ( of yew) before the surrender, thus giving rise to the name of Las Médulas.

The town of Orellán is located next to a ferruginous breccia from which they extracted the mineral to later melt it and later forge the tools used in the gold extraction work. The Villa de Pedreiras seems to have been inhabited by the Romans who were in charge of the management and exploitation of the site.

The montiun ruin was the collapse system named after Pliny the Elder, which was used in the Médulas, where the richest layers of gold conglomerate were found at the bottom of the mountain. The system was based on two techniques: first, galleries were excavated to weaken the section of the mountain that they wanted to demolish and then the water burst in with force and, as it flooded the galleries, it compressed the air and it acted like a battering ram, demolishing the limited area.

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The House of Las Médulas Park:

In Carucedo there is thePark House. If we understand by natural the original, the intact, then possibly the Las Médulas Natural Monument is the least natural of the spaces belonging to the Network of Protected Spaces of Castilla y León, since it has been precisely the human being who has caused, with its profound transformation of the environment, the current landscape. This ancient Roman gold mine, the largest in the Empire, is today an object of protection and enhancement.

But its rate of exploitation and the means used contrast with those of current technology and those of nature itself. In recent years, scientific and technological advances developed by human beings have caused the impact of their activity on the environment around them to be so rapid, so impactful, that nature cannot cushion its effect. Given the altering capacity of the human being, any effort of nature is barely appreciated. 

Three rhythms and three colors express the contents of the exhibition at the Casa del Parque de Las Médulas. The rhythm of the works of the Roman mine - orange -, the rhythm of nature - green - and the rhythm of technological advances - red -, bring us closer to discovering and knowing how human beings transform the environment around them, creating new landscapes. This transformation and the responsibility of achieving a sustainable future are the protagonists of the exhibition.

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