Season 2 Episode 11
This enormous tube tunnel will connect by rail not just the two sides of Istanbul, but two continents. And for an added challenge, they′re building the thing under water.
Below NYC, three subway projects are underway. Can they be built without disturbing the massive system already in place?
Switzerland is revolutionizing Euro transit, using the world's largest boring machine to build the longest tunnel... under the Alps!
Turkey is making a clever move by harnessing the energy of the country′s powerful mountain waterfalls—a move that involves building a dizzyingly tall dam wedged between those very mountains.
Beware the dangers that lie deep beneath South Africa, the source of the largest gold reserves in the world's deepest gold mine.