Most-visited and most-photographed slot canyon in the American Southwest.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Rippling sand dunes frozen in the Arizona rock.

A grandiose octagonal home crowned by a large dome stands out among the antebellum mansions.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

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

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

The childhood home of Earth's alien chameleon is a humble Brixton flat.

An artistic tribute to the famous singer, just around the corner from where he was born.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.

Scattered throughout London are ancient remnants of the city's former bounding wall.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

Christ's blood preserved in a Belgian town.

Visitors to this Belgium graveyard are greeted by the grieving stone parents of the young men lost to war.

This Belgian theme park began as a refuge for bored church children and was closed down when a boy lost an arm.

A Museum of Psychiatry in a still-operating mental institution.

Climb inside an iron crystal magnified 165 billion times its normal size.

Lavish royal estate punctuated with heated greenhouses.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Meet the bronze beloved pet to a family of famous peeing statues.