Switzerland sees itself as the nation of tunnels par excellence, especially since completion of the Gotthard Base Tunnel - at 57 kilometres, the longest rail tunnel in the world. There are, after all, countless tunnels criss-crossing the nation. Switzerland also built the first tunnel through the Alps - the Urnerloch, in 1708. But the country isn't alone. Some say the world's longest tunnel is in Guangzhou, China: 67 kilometres of it, all for an underground line. The 64-kilometre Brenner Base Tunnel is currently being dug between Austria and Italy. China's Bohai Tunnel, scheduled to open in 2022, is reputed to be 123 kilometres in length.
Tunnels of the world
4 Herrenknecht tunnel-boring machines
used in the two 57-km tunnels at the Gotthard.
51 Herrenknecht tunnel-boring machines
used to build the metro in the southern Chinese city of Guangzhou.
length of the entire tunnel and passage system in the Gotthard Base Tunnel.