In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

This rare volcano spews the strangest and (literally) coolest lava in the world.

A salty red wasteland in Tanzania is a breeding spot for endangered flamingos.

Exploring the wilder, more passionate sibling of Erg Chebbi feels like discovering a secret sun-kissed planet from another galaxy.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A lover's walk between hilltop towns, decorated with graffiti love notes.

Five candy-colored villages on the Italian Riviera.

"Medieval" castle built in the mid-20th century by one family.

An enormous and lavish Gothic church in Czechia.

In the town of Třeboň, carp is king.

These hut foundations are believed to be the residence of Romulus, founder of Rome.

A sculpture serving as an homage to Pope John Paul II.

This Italian stadium makes liberal use of fascist statuary to evoke classical sporting arenas.

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

In the early Roman Empire, people deemed traitors and criminals were tossed to their deaths from this rock.

This ancient market is often referred to as the oldest shopping mall in the world.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

Erotic art covers the walls of the largest ancient pleasure palace.

Ancient snack bar of the Roman Empire re-opened.