This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A historic freight system that found the true gold rush is in tourism.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

A trading post in the North Pole where children send letters.

The king of U.S. high points towers over every other peak on the continent.

The highest point in Alabama was almost completely deforested, but is now home to protected towers and trees.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

Northern Ireland's Brobdingnagian stepping stones.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

Breathtaking and huge 430 year old maps of Italy.

A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

One of the world's tallest statues is also one of its most hated.

Some Moscow residents once claimed the bizarre, contorted mass of metal on top of the building was used to manipulate minds.

This newly renovated Soviet-era outdoor exhibition center is bigger than the principality of Monaco.

Gargantuan home of Russian science.

Stalinist skyscraper built with help of cryotechnology.

Moscow's imposing monument to the Space Age.

World's largest bell sits on the grounds of the Kremlin in Moscow.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

The bomb-ravaged remains of of a colossal Neptune.

Five candy-colored villages on the Italian Riviera.

A lover's walk between hilltop towns, decorated with graffiti love notes.

These medieval skyscrapers dominate the skyline of this small Tuscan town.