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

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

17th century palace once a meeting place for politicians.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Hear the quietest sound from across the dome.

An unusual round church in London with a Templar past.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

This Danish park has celebrated the American independence day since 1912.

The final home of the legendary Danish sailor said to have lived to be 146 years old.

Denmark's famous pseudo-hill.

A complex of six forts embedded in the Rajasthan hills.

This abandoned mansion has a window for every day of the year, and is a temple for ghost hunters.

Macabre astrological automaton clock dating to the late 1400s.

Countless grotesque faces stare out from this eerie Prague art wall.

The oldest garden in Prague, once part of an medieval orchard.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

What looks like a suicide in progress is actually a statue of Sigmund Freud.

A surreal statue honoring Prague's favorite literary son.

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

Only through deep darkness and tragedy did this elaborate royal palace become a sacred temple.

This futuristic airport terminal was abandoned for decades before reopening as a hotel—with a vintage plane of its own parked out back.

A restaurant on Staten Island showcases a different grandmother’s cooking every night.

A hidden "place of interment for gentlemen."