Puntos de Interés
Geology
Mina Delfina
The Delfina Mine, also known as the Alda Mine, was a mining operation located 2 km southeast of the village of Ortiguero, in a karstic sinkhole between the Picos de Europa and the Sierra del Cuera. To this day, remains of the historical activity that took place in this location can still be found.
While the exact moment that mining operations started at the Delfina Mine remains uncertain, there is speculation that the Romans might have been the first to take advantage of the resources at this site. This conjecture is grounded in the discovery of a decorated oil lamp and of a pit with galleries within the caves, which are attributed to the later stages of Roman occupation.
However, it is not until 1827 that there is evidence that copper and silver sulphides were extracted. Back then it was called the "Mina Suerte" (Good Luck Mine) and it belonged to the Cántabra company. Records show that production of high-grade ore amounted to 3,000 tons, in addition to a large quantity of low-grade ore.
From 1958, the Ortiguero area became known for being one of the richest in grey silver-bearing copper with blue and green carbonates, when this was reported by Guillermo Schultz, a pioneer in geological research in Asturias.
Later, from 1898 onwards, ownership of the mine changed hands several times, and it had eleven different owners. During its last stage of activity, in the mid-20th century, the mine was electrified and modernised, and it produced about 100 tons of ore per day with a copper content of 1.5%, which was then subjected to concentration process to yield around 70% copper content.
Prominent among the remains at this emblematic site in Ortiguero is the headframe featuring two cages—an elegant and rusted structure positioned above a rectangular pit measuring 48 metres, which was used for extracting minerals. The site also includes a masonry building that served as a loading point for mine carts and a powder magazine. The loading dock and hoppers used to sort and transport materials can also be observed.
The rest of the facilities around the site were demolished and dumped into the main mine shaft.