This Cold War–era underground city includes offices for Mao Zedong and Lin Biao.

This ancient Chinese observatory still contains early astronomy technology.

The most famous location in China was home to whole dynasties worth of imperial rulers.

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination.

Ming Dynasty necropolis raided during the Cultural Revolution.

The field of tiny caves that mark this Chinese cliffside are each their own historic Buddhist temple.

These mountain hot springs have seen power struggles, doomed romances, and a generalissimo's attempted escape from mutiny.

An ancient fortification lives on in this Chinese city.

Although resembling a grand Buddhist temple, this structure is actually the largest mosque in China.

These rusting, skeletal structures are monolithic monuments to Glasgow's industrial past

Remnants of the Roman empire's northern frontier nestled in suburban Glasgow.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

A favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.

The heads of two giant mythological water horses honor Scotland's horselord past.

This volcanic plug boasts the longest recorded history of any Scottish stronghold.

A giant pineapple, a symbol of hospitality, and an amazing vacation rental option.

Largest lake in Great Britain measured by surface area.

Legend says a witch conjured the world's third largest whirlpool to protect Scotland from a nasty pirate.

Built to hold the worst of the worst of the Nazi war prisoners.

The Guinness Record holder for largest hedge in the world is a verdant Scottish bulwark.

A small island abbey is the final resting place of many medieval Scottish monarchs, including the real Macbeth.

Looking strangely like Rome's Colosseum, this unfinished tower has dominated the skyline for over 100 years.

A private home envelops the ruins of this 13th-century priory.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.