Diesel locomotive D # 4 of the "Petit Train d'Artouste", a 50 cm gauge tourist railroad about 10 kilometers long in the French Pyrenees at nearly 2000 meters above sea level,runing along the rockface with her train. The railroad was built between 1921 and 1924 as a construction railroad for the construction of the Lac d'Artouste dam and associated aqueduct, and was first opened to tourists as a railroad from 1932 (only on Sundays in midsummer). Today, the railroad carries about 130,000 people per season.