Tags: Tunnel.
The Guadarrama Tunnel is a railway tunnel across the Sierra de Guadarrama along the high-speed route Madrid–Valladolid in Spain. The tunnel has two tubes. The western tube is 28407 m long and the eastern tube 28418 m long and it is the longest tunnel in Spain (when not counting the Line 12 tunnel in the Madrid Metro). The tunnel was opened for traffic in December 2007. The tunnel is used by the AVE high-speed trains.