The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

This South London cemetery holds the remains of more than 15,000 people.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

James Turrell's total color immersion art installation, hidden on the top floor of a luxury handbag shop.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

America's most famous piece of self-built architecture.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

A 16th-century horror show built in a lovely Italian garden.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

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

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

Medicinal spa created with the discharge from a geothermal energy plant.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This faux-seedy Japanese arcade is made up to look like a maze of alleys straight out of a cyberpunk dystopia.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

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

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.