Ancient pueblos built into the base of a natural canyon wall.

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

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

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

An enormous public square and parade ground built to celebrate Ghana's independence.

The clever workshop that has been designing some of the most unusual coffins imaginable.

Where thousands of slaves passed through the "Door of No Return."

This series of rope-style bridges brings visitors into a jungle layer that is usually reserved for birds and monkeys.

The only quarter of the Old City not dedicated to a major world religion.

A "miracle" that seems to produce more holy fistfights than holy revelations.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

Known as the "Valley of the Moon," this Jordanian wadi is one of the most amazing desertscapes on Earth.

The most gigantic, swoony, intimidating trio of fingers in all of antiquity.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Robot jockeys ride their humped mounts to victory as part of a 21st-century twist on an ancient desert sport.

Skyscraper powered by wind turbines attached between its towers.

A striking symbol of the Bulgarian capital.

The oldest housing complex in Riga is a mini timeline of architectural trends.

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

The reconstruction of this prominent building fulfilled a long-written command.