More than 12,000 years ago, this park was a playground for mastodons.

Hundreds of graffiti artists have decorated this flood-wall on the west bank of the Mississippi River.

An old tree that is the final resting place for many pair of shoes.

The longest of the four remaining covered bridges in Missouri.

These pink granite water slides are the result of millions of years of erosion.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

The maximum security facility was once thought to have "the bloodiest 47 acres in America."

A subterranean haunt where wine and homemade biscottis are always on the menu.

Giant granite rocks standing end-to-end like a train of circus elephants.

Some of the oldest exposed rock formations in the United States.

A museum dedicated to man's boldest venture.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

Rusted and decayed, this former mining site is a portal to the past.

During World War II, the Shroud of Turin was secreted to this remote southern Italian complex.

One of the few places of its kind, this space research center sits deep in the countryside of Matera.

On the walking path from Monterosso to Vernazza, a small shrine dedicated to feline friends.

A memorial to Brazil's little-known role in World War II.

The only visible remains of this ancient Greek underground temple is its roof protruding from the earth.

Its look is severe, but its location, isolated on a hill in the middle of the countryside, is particularly scenic.

A mountain cave is the site of archaeological findings and Paleolithic rock art.

This Roman amphitheatre was also the location of the first gladiator school.

Unscathed for almost 2,000 years, the best preserved Roman triumphal arch is in a small southern Italian city.

This Italian ski resort rose to fame when Benito Mussolini was held prisoner there and then rescued by the SS.