The final tunnel, the fifty seven kilometres (35 mi) Gotthard Base Tunnel (a double-tube railway tunnel), opened in 2016. At around five hundred metres earlier mentioned sea stage, it provides for the first time a flat route in the massif as well as Alps with the northern plains at Erstfeld https://kylerkiebw.blog2freedom.com/30387169/how-much-you-need-to-expect-you-ll-pay-for-a-good-gotthard-traffic-updates