Hear the quietest sound from across the dome.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

A hidden treasure of an abandoned city lies deep in the jungles of Campeche, Mexico.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

Race through the maze, get your name on the sign.

These ancient sacred grounds granted amnesty to those who managed to reach them.

An old world fairytale-land with over 350 fairy folk figurines hidden amongst 800 year old cedars.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

A historic freight system that found the true gold rush is in tourism.

Four-story concrete hotel never opened to customers.

A trading post in the North Pole where children send letters.

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

The only road through the heart of Glacier National Park.

"Polynesia on the Plains."

Twelve plaster figures inspired by da Vinci's famed painting haunt the desert landscape above a real-life ghost town.

The best Tiki bar in Las Vegas.

The most magnificent bottle house in a town strangely full of them.