This small mining town was included in the UNESCO World Heritage Site in 2006 for its incalculable historical value. It is located 150 km south of Santiago and is known as the city of stairs since it does not have streets, its "main street" is a large staircase that leads to most of the buildings that comprise it. Its construction dates back to 1904 with the prior approval of the Ministry of Finance for the exploitation of Copper on April 29, 1905. Between 1907 and 1911 the railway that linked Sewell with Rancagua was built, today only the city center remains, the rest was demolished and dismantled in the 80s.
Sewell came to have the most modern hospital in South America. Education, health and housing were free. Its population was highly segregated between North Americans and Chileans and single and married. Its colorful buildings reached their splendor in the 1960s when it came to house more than 15,000 inhabitants, but in 1967 the nationalization of copper and the "Operation Valley" by the government began, moving its inhabitants to the Rancagua valley and ending in 1976 when the operation of the Railroad ended. Today the Sewell Foundation organizes guided tours every weekend to reveal the origins of the great copper mining in our country.