A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

Commonly acknowledged as the only public monument to the Devil himself.

Picturesque ruins once held off mighty armies.

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

In an odd geographic anomaly this city borders two different states on opposite sides of town.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

These ruins of a pre-Columbian cliff village are among the most beautiful and well preserved in New Mexico.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

Legends surround this jagged rock formation in the New Mexico desert.

Giant telescope mirrors built in a spinning furnace under a college football stadium.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

This giant steer-skull edifice refuses to die.