This hidden collection of everyday objects illustrates life within communist Poland.

A group of glacial erratic boulders are improbably balanced on white limestone pedestals.

Hidden in a metro shop under a shopping mall, this small museum tells the story of one of the world's largest urban transit systems.

A sculpture park of the tossed aside relics of the USSR, from Stalin to a massive Soviet emblem.

Museum celebrating the achievements of the Soviet space program.

Immortal combat in a Moscow museum.

Hidden beneath the streets of London is a secret subway that only carried mail.

One of the largest megalithic complexes in England, which local legend holds is a wedding party turned to stone by the Devil.

The world's largest museum devoted solely to the whirlybird comes complete with its own chopper graveyard.

Museum about life, death, and cannibalism in the Stone Age.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

Surreal riveted sea forts once protected the Kent shores from German attack.

The longest hedge maze in the world.

A museum and shop on Bourbon Street located in the former home of the second Voodoo Queen of New Orleans.

Introducing the Green Fairy to her fawning masses.

According to one local tradition, the entrance to the Voodoo underworld can be found in New Orleans through seven gates scattered throughout the city's French Quarter.

Site of a former hidden treehouse in New Orleans.

A snapshot of the city's fascinating voodoo culture.

A historic neighborhood church is reborn as a psychedelic arts collective.

A painfully obvious spy house sits right across the street from the Russian Embassy.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

A derelict bit of transportation infrastructure hidden in the woods.