Ruinas de Huanchaca, Industrial silver smelter ruins in Antofagasta, Chile.

Ruinas de Huanchaca is a former silver smelter in Antofagasta, Chile, with andesite stone walls rising against the coastal landscape. The facility consists of four distinct sections including workshops, smelting furnaces and refining areas, now preserved as an open-air monument.

Construction began in 1888 under plans by Arturo Wendt and A. Gmehling, after an agreement between the Huanchaca Mining Company and the Antofagasta Saltpeter and Railway Company to move ore from Pulacayo. The plant opened in 1892 and began refining on 26 February 1893, treating 200 tons of ore daily and producing 3.85 tons of silver monthly with over 1,200 workers. Operations ceased in 1902 because of unstable silver prices, outdated technology and the flooding of the Pulacayo mine.

The original machine room became the Military Chapel of Our Lady of Carmen in 1942, marking an industrial to religious space conversion. Since 1993 an annual Christmas concert takes place between the massive stone walls, with music and fireworks transforming the old smelting furnaces into an open-air stage.

The ruins stand inside Huanchaca Cultural Park at Avenida Angamos 01606, opposite the Enjoy Antofagasta casino. The site opens Tuesday to Sunday, 10:00–13:00 and 14:30–19:00, with free admission. TransAntofagasta microbuses 102, 103, 104, 107, 119, 121 and 129 stop nearby.

The thickness of the andesite walls reaches over one meter (3 feet) in places and was calculated to withstand the enormous heat of the smelting furnaces. The coastal location allowed direct ore transport by ship from Bolivian mines in the Atacama Desert.