The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

The mortal remains of an estimated 70,000 people lie in the basement of a monastery in Lima, Peru.

This Niagara Falls tourist trap is a world bright with neon and curiosities that will inspire love, hate, or a mixture of both.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

The Midwestern United States' tribute to Michelangelo is a foam statue sprayed with gaudy gold paint.

There aren't too many operational funiculars around, but Pittsburgh has two!

An exotic wildlife habitat right off The Strip.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

It's a pretty creepy lock-up.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Elevated freight railway turned wildly successful urban park.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

This shallow cave got its name from copious amount of human bones found inside.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

A massive sea stack famous for its appearance in The Goonies.

The longest continuous lava tube in Oregon.

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

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

These pretty kitties killed and ate as many as 135 railway workers.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A speakeasy takes on Chicago's drinking culture.