Uyuni is a city in the southwest of Bolivia. It primarily serves as a gateway for tourists visiting the World's largest salt flats, the nearby Salar de Uyuni. It is an important transport hub, being the location of a major railway junction. Four lines join here, respectively from La Paz (via Oruro), Calama (in Chile), Potosí, and Villazón (on the Argentine border, where the line now ends). One of the major tourist attractions of the area is an antique train cemetery. It is located 3 km outside Uyuni and is connected to it by the old train tracks. The town served in the past as a distribution hub for the trains carrying minerals on their way to the Pacific Ocean ports.