One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Mountain where Jesus was first tempted by the Devil.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

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

Once the home of a hermetic monk, this cave now houses a small church.

Museum dedicated to the terror regimes of Hungary.

World's tallest cigar-shaped radio tower.

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

Looming communist pillar with a Czech twist.

The titular "little arch" near this Italian resort is one of the most popular diving spots in the country.

For hundreds of years, this huge figure has been blessing visitors before they explore his body.

Massive galleon from a box-office bomb docked in Genoa.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

This one-of-a-kind archeological site is home to strange prehistoric ruins, the original use of which is still a mystery.

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

Stalactites and stalagmites in a beautifully lit cave.

The topiary maze at the Habsburg hunting lodge.

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

A sunken idol welcomes parishioners to Davy Jones' Locker.

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

Macabre astrological automaton clock dating to the late 1400s.

Giant, friendly pelicans in Central London, the most unlikely of places.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.