What is "janon"

The Janon is a small river that rises in Mont Pilat in the Massif Central of France near to Saint Étienne. It runs for through mostly built-up country to join the Gier at Saint-Chamond. The valley of the Janon and the Gier is a natural line of communication between the coal mines of Saint Étienne and the port of Givors on the Rhone. For many years there were plans to build a canal along this line. A westward extension to the Loire would link the Mediterranean with the Atlantic, but this never materialized. In 1833 the first railway in France was opened along the line of the Janon and Gier.