These tall, red sandstone pinnacles outside Moab are often forgotten amid their more famous neighbors.

The first railway tunnel to cross the Continental Divide and, at 11,523 feet, was once the highest railroad tunnel in the world.

A bronze ballot box stands at the spot where Susan B. Anthony voted illegally.

All that remains of this once-booming mining town are the ruins of a saloon.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

This 13th century Gothic brick castle is the largest in the world by surface area.

This massive home was constructed by one of the greatest conservationists in Colorado history.

The fragmented remains of a massive public bath connected to the city's water supply.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

The remnants of the base where US Army troops learned how to fight in extreme conditions.

This interpretive path lets you get up close and personal with dinosaur bones.

Each year, teams of the world's best snow sculptors have 65 hours to create frozen masterpieces.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

This spectacular track has run continuously since 1882.

Go inside to really appreciate this 500-year-old technological masterpiece.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

Cliffside houses provide a spectacular view from their perch above the valley.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

Stunning Roman aqueduct used for 1900 years and still standing.

Historic medieval fortified city in southwest France.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

A Black Forest cuckoo clock theme park features one timepiece big enough to walk inside.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.