The crossing of the Alps is an important route for European transportation, as the Alps separate Northern Europe from Southern Europe. Alpine railway routes began in 1882 with the Gotthard Railway with its central Gotthard Rail Tunnel, followed in 1906 by the Simplon Tunnel and the Lötschberg Tunnel in 1913. As part of the New Railway Link through the Alps (NRLA) in 2007 the Lötschberg Base Tunnel opened and in 2016 the Gotthard Base Tunnel opened on 1 June.