Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

"Stairs of the Turks", a chalky white cliff eroded conveniently into stairs, allowing for easy pillaging.

This Italian foot path winds through the mountains via 52 individual tunnels.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

This zoological museum began as the first great curiosity cabinet.

Five candy-colored villages on the Italian Riviera.

The mountaintop inspiration for Umberto Eco's "The Name of the Rose."

When this funny little building went up in the 19th century, most people thought it would simply fall over.

Now an entertainment complex, the Lingotto building was once an avant-garde auto factory with a test track on the roof.

A fake medieval village in the middle of Turin.

The astonishing collection of an infamous criminologist.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

It's good luck to be mocked by this monkey.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

The world's longest and deepest train tunnel.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Archduke Ferdinand II's collection of rare objects is considered one of the oldest museums in the world.

Swarovski's museum/theme park is a fake diamond fantasia overlooked by a giant.

This splendid tomb may look fantastic, but there's nothing in it...

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

The world's first experimental nutritionist is memorialized as the "Hippocrates of naval medicine."

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.