This curious, round temple is the oldest still-standing marble building in Rome.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This cheese shop also houses a museum devoted to Dutch dairy.

The cheese slicer may be a Norwegian invention, but the biggest ones in the world are found in Sweden.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This tumultuous Icelandic lava field looks so alien European researchers want to use it as a stand-in for Mars.

The most powerful waterfall in all of Europe.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Walk in the footsteps of the gods and straddle two tectonic plates.

This wild explosion of color on a disused water tower tells the whimsical tale of a curious puffin.

Eerie ruins of an abandoned medieval fishing village crumble atop an unforgiving stretch of earth.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

Medicinal spa created with the discharge from a geothermal energy plant.

A concrete mushroom that divided Stockholm residents for nearly a century.

A remarkable feat of Victorian engineering across the Firth of Forth.

Beatlemania is still going strong... at least in Kazakhstan.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

Barça football fans might see the insignia hidden in a church window as a divine sign.

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."