This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.

This sacred, circular cave is lined with pools so clear and still that it's hard to tell where the water begins.

This reserve is the only place in the world where you can see the Barasingha swamp deer in the wild.

An exotic jungle hideaway run entirely by indigenous Kichwa women.

Dozens of lights dangle from the branches of what may be the brightest tree in Los Angeles.

Crushed coral and crystals give the sand its signature coloration.

This ancient oak tree plays matchmaker for singles willing to branch out from the usual dating scene.

A giant toy jack made of numerous welded-together fire hydrants.

Obscure Freemasons still live in D.C.’s largest private residence.

Over 1.3 million confiscated wildlife products fill this macabre menagerie of illegal animal specimens.

A small poultry graveyard in the courtyard of a popular Key West watering hole.

The world's largest grapevine has produced a delicious harvest at Hampton Court Palace for almost 250 years.

Beautiful antiques and obscure engineering artifacts trace the evolution of phones from rare luxuries to ubiquitous.

The largest radio telescope in the world searches for extraterrestrial life from the remote limestone peaks of southern China.

A jungle cave in Peru of unknown depths, otherworldly sounds, and strange nocturnal birds that navigate by echolocation.

This quiet park's strange sedimentary spires were named after Kodak's color film.

The medieval network of canals hidden underneath the city is opened to explorers each year.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

An abandoned Soviet-era mining town in the mountains of South Kazakhstan.

This isolated structure beckons adventurers with sublime views of the Faroe Islands.

A shrine-like museum entirely dedicated to soccer superstar Cristiano Ronaldo.

This massive swimming pool is the high tech home to the human-powered submarine races.

The early data processor factory founded in Washington for the 1890 U.S. Census went on to become IBM.