A memorial for military police dogs in the former U.S. air base.

Once the site of seances, this restaurant is said to be haunted by several ghosts.

An overlooked memorial honoring the local Washington residents who died in World War I.

This tombstone marks the spot where the legendary British spy met his end.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

Could this controversial parietal bone be the remains of the famed French philosopher?

The world-record holder for the longest bridge stretching continuously over water.

Outside of one of Britain's most renowned social clubs, a step installed specifically for the Duke.

A former Canadian Pacific Railway station turned liquor store, the first and only station in Canada visited by British royalty.

A saloon and inn that served the Wild West's most iconic figures—and is still haunted by some of them today.

Nestled amid the peaks and lochs of the Scottish Highlands, this inn and pub has played host to outlaws and ghosts.

An early-19th-century hotel with a past that is steeped in the Civil War.

This centuries-old hotel hides a network of secret cellars and passages once used by smugglers.

In the middle of a remote desert town is a surprisingly opulent hotel.

This grisly effigy displays an early Christian martyr who was skinned alive and beheaded.

This public observatory is home to the "celestial cannon," the longest pointable telescope in the world.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

A dark, narrow tunnel that leads to a charming lake and waterfall.

Step back into the glory days of Florida's nascent tourism industry at this Gilded Age palace.

The site of an early Arthurian battle and the dwelling-place of prehistoric people and (possibly) an ancient race of giants.

Over 100 concrete munitions bunkers are all that remain of a Pennsylvanian village seized by the US government.

Local stories say that if you drink from this well, you will return to Olympia.

Water of undetermined depth has attracted rare fish and cult leaders alike.

Sit at the "Disney table,” where Walt and his team of "imagineers" once dined on the regular.