Humberstone Saltpeter Works, UNESCO World Heritage Site, northern Atacama, Chile, South America

humberstone saltpeter works chile atacama train carriage rusted metal industrial building corrugated roof weathered paint stacked dust dimly lit abandoned derelict ruin ghost town heritage history unesco northern chile south america travel landscape architecture transportation industry mining excavation extraction processing refining chemical fertilizer nitrate sodium nitrate 19th century 20th century industrial revolution industrial site post industrial industrial tourism historical site historical landmark cultural heritage cultural landscape