Many years of hard work have finally ended: the Simplon Tunnel was finally drilled through the Alps. Passing at an altitude of 700 meters above sea level, the tunnel ran next to the eponymous mountain pass and was the longest tunnel in Europe at 19 thousand 800 meters.
In 1922, the number of Simplon tunnels doubled. Both tunnels link the city of Brig in Switzerland with Domodossola in Italy. And the world’s longest tunnel runs under seabed and connects the islands of Honshu and Hokkaido. Those who suffer from claustrophobia should better not venture there – the Japanese tunnel is more than fifty kilometers long.