Chacabuco
Sierra Gorda, Chile
Chacabuco is one of the many abandoned nitrate or "saltpeter" towns ("oficinas salitreras" in Spanish) in the Atacama Desert of northern Chile. Other nitrate towns of the Atacama Desert include Humberstone and Santa Laura Saltpeter Works. Unlike most of the other ghost towns in the Atacama Desert, Chacabuco became a concentration camp during the Pinochet regime in 1973. To this day, it remains surrounded by approximately 98 lost landmines, left by the Chilean military when Chacabuco was used as a prison camp.
Monument data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).