María Luisa Pit Monument · Langreo, Nalón, Asturias A coal mining operation in Ciaño, Langreo, active since 1858 through the María Luisa adit worked by the Unión Hullera de Santa Ana, a French-owned company, and deepened into a shaft in 1918, not reaching full output until 1942. It closed on 31 December 2016, the last mine in Langreo to do so. A firedamp explosion that killed seventeen miners in the 1940s led to the song «Santa Bárbara Bendita» being adapted with new lyrics, «En el pozo María Luisa», now the best known version. In 1976 King Juan Carlos and Queen Sofía went down into the mine dressed as miners, a visit later repeated by President Adolfo Suárez. The exterior preserves two buildings from the 1920s, of crenellated red brick, the loading pavilion, the headframe and a mine entrance from 1897, today a chapel. Photo: LMLM (CC BY-SA 4.0) What to see and do in Langreo