This hunter-gatherer architecture is believed to be the oldest religious complex known.

A semi-abandoned village destroyed by U.S. bombings during World War II dominates the valley of Turano.

A swath of France so devastated by war it is still forbidden to go there.

A rare example of this century-old British tank stands near the center of town in Ashford.

This memorial museum chronicles the apocalyptic destruction of the First World War.

A unique museum tells the story of the day-to-day life of World War I soldiers.

This pink watchtower served as the seat of the Greek government after independence from the Turks.

This fortress played a key role in the battle that would ultimately give rise to the Maratha Empire.

This foreboding medieval castle was twice besieged by barons rebelling against the English king.

The birthplace of the ferocious William the Conqueror, this castle is awash in medieval history.

Henry VIII's forgotten castle was built by the gunpowder-obsessed king to be defended solely by cannons.

Buried next to Pompeii, this lesser-known Roman villa was the opulent vacation home of Emperor Nero's wife.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

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

An extraordinary mix of Phoenician, Roman, early Christian, and Byzantine ruins beautifully set overlooking the Mediterranean.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.

There's a labyrinth of manmade tunnels stretching for over an acre beneath Bristol.

An abandoned canal route lies hidden under the streets of Manchester.

Scotland still bears an enormous scar of its Roman past.

One man's quest to fix his toilet unearthed over 5,000 artifacts spanning more than 2,000 years of history.

The world's oldest map of the holy land gives us a fragmented glimpse of the layout of biblical nations.

These 18th-century paintings of Warsaw were used to reconstruct the city after World War II.