This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

An abandoned textile factory on the "island of crows" was home to Estonia's first workers' strike.

The ruins of an Estonian prison are drowning in the quarry lake where the convicts were once forced to work.

Mysterious craters may have been home to an ancient cult.

Around 160 years ago, this spot marked the location of a wharf along the shores of the Charles River.

Historic Hull Street was actually the first street with a proper name in the Boston area.

The last remaining 19th-century tenement from Boston's old West End neighborhood.

A 400-square foot model of historic Quebec is the playing field for a state of the art light and sound show.

Train tunnel running underneath Quebec City.

This extensive collection of vintage Soviet cars is the only one of its kind in the Caucasus.

When the Soviets destroyed the historic Armenian monastery they somehow left its bell tower intact.

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.

Luxury hotel turned into a refugee camp, then turned back into a luxury hotel.

The secret room where early Bolsheviks cranked out propaganda fliers on a smuggled printing press.

A small but hugely whimsical theater where marionettes play out the "The Battle of Stalingrad."

You'll find just about anything in this funky Tbilisi flea market.

Unusual building appears to be haphazardly built from randomly piled bricks.

A trompe-l'oeil statue honoring the first guide dog in North America.

This classic red schoolhouse is said to have been where Mary and her little lamb went to school.

This campus museum commemorates a national tragedy.

But did the famous feminist and abolitionist ever really say those iconic four words?

Memorials and tributes scattered across the university grounds remember a famous national tragedy of the Nixon era.

The unique collection includes bronze cast handprints of some of America's most famous astronauts.

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.