Wearing a red hard hat and carrying a backpack with an emergency oxygen tank, I’m sweating as I get a rare look at the newest wonder of the world—the 35.4-mile Gotthard Base Tunnel ...

The metal tracks inside the tunnel leading into the 3.7-mile ... the lookout to see expansive views of Donkey Mountain and ...

Stumphouse Tunnel offers a rare glimpse into an unfinished railroad project that never came to be. Dark, eerie, and full of ...

Maybe that's because it's also one of the world's steepest roads, chiseled into the mountain by local villagers. The Guoliang Tunnel is located in the Taihang Mountains in China's Henan Province ...

The Zoji La Tunnel, which is set to be the longest in Asia, will pass under the Zoji La pass in the Himalayas, the world's highest mountain range. The aim of the tunnel is to provide year-round ...

Here's how the tunnel boring machine, or TBM, works: As the 200-ton TBM moves forward, a round cutter head studded with titanium teeth grinds into the tunnel face and splits large chunks off the rock.

Thousands of workers are battling the elements to build India's longest tunnel in the Himalayas. But the Zojila tunnel has a greater purpose, as it could be a game changer for India in the country ...

When it opened on July 4, 1930, it was the longest mountain tunnel in the U.S. Today, the sandstone tunnel is a major thoroughfare and top Zion National Park attraction. As you drive through it ...