Mysterious hillside with a continuously burning natural fire.

Remnants of the city's Soviet history hover over this modern fast-food outlet.

This site contains overlapping ancient graveyards that existed about 1,000 years apart.

Mysterious lost empire of the Silk Road.

At the height of alum production at this factory, human urine was a valued commodity.

The healing properties of this well attracted royals and commoners throughout the Middle Ages.

This hidden 13th-century tavern room has a few Shakespearean connections.

This astronomical clock is the second oldest in England.

The ruins of this medieval castle on a foggy hill tell the story of a once-mighty empire.

The famous greeting card maker owns a collection of paintings by the famed surrealist.

This ancient Visigothic church might hide an ancient treasure.

The oldest residential street in Europe also features an optical illusion.

On a small island in the Caribbean, a statue of Napoleon's first wife has been beheaded and covered in red paint.

An artist's whimsical transformation of everyday objects.

A functioning Roman-era aqueduct and bridge in rural southwest France.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

Underneath this small church are 15,000 bones, arranged by an obsessive academic.

Underneath the city that invented pilsners are a series of historic tunnels that have been storing beer for centuries.

The 14th-century ruins are said to contain healing powers.

An army of sleeping knights sculpted by a self-taught local artist beautifully depict an old Czech legend.

In the town of Třeboň, carp is king.

A peculiar samurai statue overlooks the center of Brno.

This little museum has an exhibit devoted to the elusive forest denizens.