Switzerland means chocolate. Neutrality. Heidi. And the Alps. But particularly the Alps. They extend over more than half of the country and epitomize "Switzerland" to the rest of the world—and even to the Swiss, who don′t have a common language to connect them. Those snowy peaks divide the country geographically, but symbolically they unite it, a scenic and impressive source of national pride.

They′re also in the way. The Alps bisect Switzerland, and therefore—since Switzerland is smack in the center of Europe—they bisect Europe. There′s a giant port in Rotterdam to the north, and to the south, there′s the mammoth port of Genoa. To get goods from one side to the other, you have to deal with these mountains blocking your path.

For 125 years the way past has been the Gotthard Rail Tunnel. This tunnel takes trains up one vertical mile in a tight spiral, then across the top, and then back down in a tight spiral. It′s slow and, since half of it is a fight against gravity, it requires short trains and extra locomotion—an engine to pull and a caboose to push. You look at it and you think, why not just go straight through? Wouldn′t that be simpler?

Well, yes. Going straight through is simple. That′s what they′re doing at the Gotthard Base Tunnel, essentially starting at the tunnel base and drilling at that same altitude all the way through the Alps. It′s simple, but it′s not easy.

To make a tunnel through a mountain, you have to drill through rock. Simple! Not easy: For the Gotthard Base Tunnel, they are using four Tunnel Boring Machines (TBMs), each the length of four football fields. The problem is that, because of the way the Alps were formed (two tectonic plates crashing into each other and pushing up a mountain range), the rock they′re drilling through is vertically rather than horizontally layered. Which means that the TBM might have be chewing through some of the hardest granite on earth one minute and then, the next minute, face something far softer and prone to caving-in. TBMs don′t like that; they like consistency. Here at the Gotthard Base Tunnel they don′t even get predictability. One of the engineers told me it would be easier for him to describe the rock on the surface of the moon than whatever was at that moment in front of the TBM.

Not easy. But when they′re done, in 2017 (if we′re to credit Swiss punctuality), it will be the longest tunnel in the world, stretching 36 miles through a once solid mountain.

When they′re done, you′ll be able to get from Zurich to Milan in just over two hours. When they′re done, goods that are now trucked around Europe will be cheaper to ship by train, taking an untold number of trucks off the road.

When they′re done, a famously divided people—made up of the Swiss Italian, the Swiss German, and the Swiss French—will be drawn closer together. And the whole of the European economy will work a little bit more . . . well, like a Swiss watch.

There. Now I think I′m all out of Swiss clichés. Did I mention chocolate?