A swing to dangle you off the very edge.

The oldest hotel in the world has been operated by the same family for over 1,300 years, even catering to samurai.

A Spanish-style estate that has traded black ties for rock concerts.

The haunting ruins of a military fortress turned astronomical observatory sit on a Sarajevo mountaintop.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

The latest in a series of long glass bridges suspended at terrifying heights.

Years of archaeology, just chillin' by the water cooler.

One man's swirling six-acre monument of stone.

This subterranean disco dance club in a Cuban cave comes with bright lights and a dark legend.

A Buddhist temple to honor insects that died for science.

Buildings from the fictional planet of Tatooine still litter the Tunisian desert.

This stunning mass of ice spans 121 square miles and is still growing.

A medieval stronghold rising over the ruins of ancient Roman villas along Rome's southern coast.

This deceiving white sand beach gets its brilliant hue from the chemical discharge of a nearby factory.

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

This military mausoleum captures the solemn grandeur that most memorials only aspire to.

The skulls and bones of thousands of soldiers line the walls of this small Italian chapel.

Long-abandoned art nouveau baths beneath Milan's Piazza Oberdan.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

Renaissance villa and gardens complete with a tormented colossus.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

Now an entertainment complex, the Lingotto building was once an avant-garde auto factory with a test track on the roof.

A visionary Italian architect created an impressive cluster of concrete structures for a family's private tomb.