Ferrocarril de Antofagasta a Bolivia

The Ferrocarril de Antofagasta a Bolivia (British company name: Antofagasta (Chili) & Bolivia Railway or FCAB for short) is a private railway operating in the northern provinces of Chile. It is notable in that it was one of the earliest railways built to 2 ft 6 in (762 mm) narrow gauge, with a route that climbed from sea level to over 4,500 m (14,764 ft), while handling goods traffic totaling near 2 million tons per annum.

Source: Wikipedia — Ferrocarril de Antofagasta a Bolivia (CC BY-SA 4.0)