Sewell is an uninhabited Chilean mining town located on the slopes of the Andes in the commune of Machalí in Cachapoal Province, Libertador General Bernardo O'Higgins Region, at an altitude of between 2,000 and 2,250 metres. In 2006, it was designated as a UNESCO World Heritage Site. It is known as a former company town, developed by Braden Copper Company for housing the workers (and their families) associated with the operations of El Teniente, the largest underground copper mine in the world.