One of the figures in this Celtic sculpture continues to puzzle archaeologists.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

A miniature village mimics the surrounding buildings so well it includes itself.

Moonbows over Kentucky.

The world's longest known cave system.

River pirates, murderous bandits, and serial killers used this Illinois cave as their debauched hideout.

Known as the "Cross At The Crossroads," this massive metal cross is just short enough to avoid the FAA.

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.

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

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

A naturally mummified 2,000-year-old man.

Famously misunderstood wonder of the ancient world

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The fairy tale castle of the "fairy-tale king."

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.

An office built to look like a giant basket.

Baroque celebration of the end of the Great Plague of Vienna.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

The topiary maze at the Habsburg hunting lodge.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

The final resting place for the remains of 143 Habsburg royalty.