Construction crews are tasked with building a state-of-the-art oil rig.

In a series of engineering firsts, two interstate highways are being rebuilt beneath Boston, sending its traffic 120 feet underground! The "Big Dig" will take more than 30 years to build, but not without confronting unprecedented challenges.

The futuristic concept of Transatlantic rail travel could be a reality.

A Bering Strait bridge would span across the Arctic Ocean's violent seas.

The New Bay Bridge is the biggest construction project in California history. This two-mile, earthquake-proof road will replace the most heavily trafficked bridge in the country-the span linking San Francisco to Oakland and the East Bay.

A massive gas refinery must be moved from Spain to the Arctic Circle.

The El Cajon Dam in Mexico will be the highest rock-filled dam ever.

The Woodrow Wilson Bridge is being reconstructed to handle today's traffic.

The longest cable car lift in the world is being constructed in Hong Kong.

Ski Dubai will be the largest indoor ski resort in the world.

The Gotthard Base Tunnel will be the longest tunnel in the world.

Hawking explores the question of whether time travel is possible.

"Are We Alone?" An eye-popping journey from the moons of Jupiter to a galaxy perhaps not so far, far away in search of alien life. We'll see what aliens might look like, question what it means to be alive, and calculate the odds of making 'contact'.

Stephen Hawking spans the entire life cycle of the universe.

The greatest mind since Albert Einstein, Stephen Hawking tackles the question: Is there a meaning to life? Is there a purpose to our existence?

Stephen Hawking attempts to explain why the universe exists.