In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Op-art architecture designed for happiness.

Apartment complexes built into huge repurposed natural gas tanks.

A unique tribute to the millions of animals who served and died for the British military.

One of the greatest movie directors of all time lived and worked in this London flat from 1926 to 1939.

A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

These two 15th-century metal rods allowed people to check if they were swindled or not.

Baroque celebration of the end of the Great Plague of Vienna.

Designed as a reminder of one of the darkest moments in Austrian history.

Hidden in the forest are the crumbling, graffiti-covered remains of the factory where most of Germany's explosives were produced during World War II.

This supermarket is suspended 25 feet above an interstate highway.

A community of collapsing homes more than a mile out from the Florida coast.

A time capsule of Floridian history fights to survive on the banks of Chokoloskee Bay.

Decorative shell walls built in the 1940s sit atop an ancient midden created by the Calusa Native Americans.

The smallest post office in the United States is no bigger than a broom closet.

Wading through a small lagoon reveals a secret, wild stretch of pristine beach.

An abandoned vacation home spent a decade taking on legends. It's now taking on water.

A massive rotating globe sits at the center of Babson Park.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

This tower pays homage to a legendary Viking fort established in Massachusetts that never really existed.

This isolated airport in the middle of the Everglades sees more alligators than planes.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Millions of numbers carved in glass represent the tattoos forced upon victims.