Sewell, the Andes Mining Town Where Staircases Replaced Streets

High in the Chilean Andes, more than 2,000 metres above sea level, there is a town where cars never drove because there were no streets. Sewell, built for the workers of the world's largest underground copper mine, was organised around a giant central staircase, and at its peak in 1968 it housed about 15,000 people who went everywhere on foot, up and down steps.

The story starts on April 29, 1905, when Chile's Finance Ministry authorised the American Braden Copper Company, founded by engineer William Braden, to work the El Teniente copper deposit, which had been abandoned since the late 19th century. A small, scattered camp grew next to the mine, known at first as El Molino or El Establecimiento.

The name came a decade later. In March 1915 the camp was renamed in honour of Barton Sewell, the company's president, who died in New York that year. According to Chile's National Cultural Heritage Service, he never set foot in Chile or saw El Teniente, but he had backed Braden's gamble on the mine.

The slopes of Cerro Negro were far too steep for wheeled vehicles, so the builders did something unusual. Chile's National Monuments Council notes that Sewell has no geometric blocks at all: each building sits wherever the terrain allows, and all internal routes are pedestrian paths and stairways. The backbone is the Escalera Central, which climbs from the railway station to the top of the town, with small squares and secondary stairs branching off it.

The houses were built of native timber, up to three or four storeys high, which was exceptional for a mountain camp, and painted in bright green, yellow, red and blue. One block, Building 152, was the only one built against the slope, with nine stepped floors. The town had a hospital, a fire station, a social club, an industrial school and a cinema.

Everything arrived by train. A narrow-gauge railway climbed from the city of Rancagua, about 60 kilometres away, and was the town's lifeline for decades. Life on the mountain was hard: winters brought heavy snow, avalanches and the constant risk of accidents linked to the mine.

The end came with nationalisation. The Chilean state bought 51% of the company in 1967 and took full control of copper in 1971. Keeping families on the mountain was expensive, so workers were gradually moved to Rancagua and the new Carretera del Cobre, the Copper Highway, replaced the railway. Many buildings were demolished before a conservation policy stopped the destruction.

What survived is remarkable. Sewell became a National Monument in 1998, and on July 13, 2006, UNESCO added it to the World Heritage List as an outstanding example of a company town. The protected area, 17.2 hectares, keeps about 38% of the original housing and 80% of its industrial buildings, according to UNESCO. The state copper company Codelco still runs a working concentrator there and opened a copper mining museum in the old industrial school.

Today nobody lives in Sewell, and private cars are not allowed up the mountain. Visitors arrive on organised tours and climb the same stairs that once served as the town's only streets.

Sources: UNESCO World Heritage Centre; Consejo de Monumentos Nacionales de Chile; Servicio Nacional del Patrimonio Cultural; Codelco, history of the city of stairs; Codelco, a mining settlement of universal value; Memoria Chilena, Biblioteca Nacional; Wikipedia, Sewell, Chile. Cover: Main staircase of Sewell, Hiroki Ogawa, CC BY 3.0.jpg).