The Roman historian, Pliny the Elder, probably referred to the iron beds of Triano when, in his Natural History, he mentions an iron mountain located in the vicinity of the ocean. The richness of the ore, its important concentration within a reduced space and its proximity to the sea enabled the intense and early start-up of this mining nucleus.
For centuries, the exploitation of the mines was undertaken by locals from the region; but, during the last quarter of the 19th century, the massive entry of capital and workforce proceeding from the rest of the Basque Country, Old Castile and Galicia, accelerated extraction from areas as well-known as Marruecos and Triano. At the same time, the landscape and social structure of the communities implied in the same were severely transformed.
Land communications linked to the mining sector, particularly the railway, experienced decisive improvements.
The rapid exhaustion of the best veins led to the exploitation of sub-products, such as carbonate, “chirta” and “miñón” and to this avail, specific infrastructures were set up, such as kilns, washing facilities and settling ponds, respectively.