The City of Staircases: How a Mining Town Defied the Steep Andean Slopes

Countries & Cities · Published 29 September 2026 Swipe more like this →

In short: Perched 2,000 metres high in the Andes, Sewell was once a bustling company town for the world's largest underground copper mine. With no roads for cars, its residents navigated a vertical labyrinth of staircases. Today, this abandoned industrial marvel stands as a protected UNESCO World Heritage Site.

Founded in 1906 by the Braden Copper Company, Sewell was built to support the extraction of copper from the El Teniente mine. Named after the company's first president, Barton Sewell, the town was an engineering feat constructed on terrain too steep for wheeled vehicles. Residents relied on a narrow-gauge railway for supplies and movement, while pedestrians traversed the town via a central staircase, the Escalara Central. At its peak in 1960, the town housed some 16,000 people, living in brightly painted timber homes that clung to the mountainside.

Life in the town was defined by both isolation and extreme environmental hazards. Beyond the daily challenge of navigating vertical paths, the community faced constant threats from earthquakes, avalanches, and industrial accidents. A devastating 1944 avalanche claimed 102 lives, and in 1945, the 'Smoke Tragedy' at El Teniente resulted in 355 deaths from carbon monoxide poisoning. These disasters eventually forced the government to adopt more rigorous safety regulations for the mining industry.

The town's decline began in 1967 when the Chilean government acquired a majority stake in the Kennecott Copper Corporation. Following the nationalization of the mine in 1971, the state-owned company CODELCO began relocating families to the valley, facilitated by the construction of the Copper Highway. While demolition of the town began in the 1970s, preservationists successfully campaigned to save the site for its historical significance. Declared a National Monument in 1998 and a UNESCO World Heritage Site in 2006, the remaining 50 restored buildings now serve as a testament to a unique industrial past.

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