One of the largest amphitheaters in Europe is a former Nazi gathering place that still stands today.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

On this Polish road, an optical illusion makes cars seem to roll uphill.

What looks like a crashed Zeppelin is actually a bright, airy reading room perched atop a modern museum.

Walk through Czech history in Prague's largest graveyard.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

This giant wire frame man sculpture is crouched in contemplation.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

A radio telescope for listening to the stars, based in one of the cloudiest countries in the world.

The struggle of a small Dutch island against the sea.

Home to the "Rat King" of Nantes and other wonders of the natural world.

The largest underground church in Europe.

Lady Liberty's original designer installed a little clone in this French fountain.

A castle-like sea fort from the 17th century is now a museum to oyster farming.

A quarry cum sculpture park where the works of art are chiseled into the very walls.

Stunning Roman aqueduct used for 1900 years and still standing.

A garden in Lisbon filled with giant porcelain creatures.

You can cross from one country to another in a single hop on this little bridge.

Hoax, mistake, or evidence of dinosaurs in human times?

Ottoman-era houses lovingly preserved.

Have fun at the world's first Buddhist waterslide park.

A British plaque explains that a house was built using the spoils of the first international golf bet.

Small museum dedicated to the founder of electromagnetic theory.