C-9

Line C-9, formerly known as the Guadarrama Electric Railway, is a narrow-gauge mountain railway incorporated into Madrid's Cercanías commuter rail network. The line is operated by Renfe Operadora and runs through the Guadarrama Mountains from Cercedilla, Madrid to Cotos Pass, Segovia. Although classified as a commuter rail line, Line C-9 primarily serves the ski resorts at Cotos and Navacerrada Passes, connecting with the rest of the commuter rail system with the Line C-8 at Cercedilla Station. Line C-9 is the only metre-gauge railway among the Cercanías Madrid lines.