At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

This replica of an 8th century burial ship actually sailed to Norway before returning home to Minnesota.

This Transylvanian church has changed its denomination four times.

An underground city of salt.

This massive underground salt mine now holds a sci-fi theme park in its depths.

A former imperial sea-fortress and Soviet prison.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

Historic slum of Tartu.

The secret cells in the basement of the KGB's Estonian "Grey House" have been preserved as a grim Cold War museum.

Tucked away in a Prague park, a statue beloved by romantics honors a poet so nice they buried him twice.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

A surreal statue honoring Prague's favorite literary son.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

Steadily reminding Czechia of its past.

Dedicated to the unsung history of human waste.

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

Monument to a suicide protesting the Soviet invasion.

Looming communist pillar with a Czech twist.

This automated sculpture of two men peeing will spell out text messages with their micturition.

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

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.