This highest bridge in the world spans such a great chasm that it had to be established using rockets.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

Site of the greatest known waterfall that ever existed.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

A building so large that it has its own weather.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

One of the smallest towns in the United States.

An American city stranded at the tip of a Canadian peninsula where strict adherence to the "49th parallel rule" became problematic.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

One of the most accessible undersea plane wrecks in the world.

The king of U.S. high points towers over every other peak on the continent.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

Watch the newest land on the planet form before your eyes.

Portlandia is the second-largest copper repoussé statue in the United States.

An apocalyptic seismic event creates a deadly chain reaction that ends with a 6-mile long lake developing within weeks.

Where the line between entertainment and aerospace blurs.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

The highest point in Washington state is a volcano covered in glaciers.

The remains of the iconic train crash from the movie The Fugitive can still be found rusting along the Great Smoky Railroad.

The largest pool at its elevation sits on top of one of the most expensive resorts in the world.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

The oldest (maybe) swimming pool in Iceland is a stunning oasis built into the side of a lush hill.

Water of undetermined depth has attracted rare fish and cult leaders alike.

This long, dark tunnel is open to hikers, but those without lights are known to get confused even on the straight path.