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

This lonely memorial marks the supposedly haunted site of a brutal 19th-century murder.

A 2,000-year-old engineering wonder hides beneath an Italian town.

Traveling this mountain pass reveals quaint stone buildings, stunning Irish scenery, and a bridge said to grant wishes.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A bronze bust commemorates the heroism of the secret agents who led covert operations against the Nazis.

Carved initials which are nearly 500 years old preserve the deposed Queen's presence at Hampton Court Palace.

The world's largest grapevine has produced a delicious harvest at Hampton Court Palace for almost 250 years.

What was once thought to be a wellspring of unicorn bones is actually just a prehistoric burial site.

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

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

It's believed King John of England stayed at this 13th-century castle before riding off to sign the Magna Carta.

This early Norman castle was the first historical monument protected by an act of Parliament.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

This medieval sanctuary's tree-framed door looks like a portal to a mythical realm.

An ancient city exhumed from the depths of the ocean.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

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

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

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

A Roman spa buried deep beneath the City of London.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

This belfry is all that remains of the town that was buried by a violent volcano eruption.

A melting pot of Asian-Pacific art features one symbolic sculpture from each of 20 different nations.