One of Vietnam's most iconic landmarks was built by Japanese traders and is now in danger of sinking.

This expansive bridge in the Canadian wilderness was originally just built for friends.

A cave covered with bizarre stalactites of cloth.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

Holy Hindu shrine in an enormous, monkey-filled limestone cavern.

The subterranean sanctuary home to local shamans is a sacred site for people of all religions.

This defunct, fortress-like prison has been the setting for several movies.

Home of an evil witch famous within southern folklore.

A plaque memorializes the Boston location of one of the largest nightclub fires in history.

The site of one of history's most indelible and horrific tragedies.

A plaque marks the site directly below the mid-air detonation of the atomic bomb over Hiroshima.

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

You don't have to be an ambassador to dine like one.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

One of the oldest wine cellars in Germany is now a restaurant beneath Bremen's town hall.

The tallest city hall in the world offers an excellent bento box.

Eat a Nobel banquet from any year in the basement of Stockholm's City Hall.

A 115-year-old restored German dining hall awaits those who venture beneath the Minnesota State Capitol.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.

What looks like a link in Gondor's early warning system is actually a centuries-old Italian fortress.

A rare example of an ancient Japanese hill castle believed to be the fortress of a legendary demon.

This iconic sluice gate is a favorite haunt for joggers, fishing enthusiasts, and even ghost hunters.

A shrine dedicated to a 10th-century samurai emperor, whose head is not buried on site (contrary to popular belief).