Building Giants: Season 2, Episode 6

2 - 6: Mega Mountain Tunnel

As engineers race to build a brand-new train tunnel beneath the Alps, they use cutting-edge tech and the latest construction methods to build the world's longest underground railroad in some of the most dangerous conditions on earth. The Brenner Base Tunnel will be 34 miles long through the base of the Eastern Alps beneath the Brenner Pass. It will run from near Innsbruck, Austria to Fortezza, Italy.