Penal Detachment of Bustarviejo Curiosity · Bustarviejo, Sierra Norte, Madrid The Bustarviejo penal detachment, known locally as Los Barracones, was a Francoist forced-labour camp that operated from 9 November 1944 to 1952, 1.5 kilometres from the village, on the slopes of the sierra de Guadarrama; it was one of nine camps the dictatorship set up around Madrid to complete the direct Madrid-Burgos railway, begun in 1920. Built for 250 prisoners, it housed as many as 2,000 at first; close to a thousand political prisoners, in conditions of semi-slavery, built the La Gargüera viaduct, two tunnels and the Bustarviejo-Valdemanco station. Alongside the railway line, the remains of the camp and its barracks are preserved today; it was recognised as a Lugar de Memoria Democrática (Spain's official designation for sites of memory of Francoist repression) in 2026. Photo: Rodelar (CC BY-SA 4.0) What to see and do in Bustarviejo