Pozo Calero

The Pozo Calero is a coal extraction shaft in the mining area of Barruelo de Santullan with a 15-meter stone headframe and access to 22 kilometers of underground passages extending to a depth of 480 meters (1,575 feet). The structure was built with stone masonry and contained multiple shafts for extraction and ventilation.

Construction began in 1911 by Northern Railways Company of Spain, though operations were delayed until 1918 due to equipment shortages from World War I. The shaft became a major feature of coal extraction in this region for decades afterward.

The shaft was a central workplace for local families and shaped daily life in the mining village for decades. Today it stands as a reminder of the underground labor that connected generations of workers to this place.

The site is best visited on weekdays when fewer people are around and you can explore the former workplace at a relaxed pace. Access to the underground passages is restricted and requires advance arrangement with local guides.

The stone masonry construction was unusual for its era when metal headframes were the standard approach. This technical choice made it a noteworthy example of traditional building methods applied to industrial mining infrastructure.