RER C
The Ligne d'Auteuil closed in 1985 to make way for the "Réseau Express Régional" (RER) C line. The RER C has been extended to Montigny-Beauchamp and Argenteuil after the construction of a new tunnel crossing north-west Paris. The line branches off at Champ de Mars, crossing the Seine. From there the line is underground; the Ligne d'Auteuil was covered in 1988, and the line between Henri Martin and Courcelles was reduced from four tracks to two. It exits Paris in a tunnel ending in Clichy.