17th century streets hidden under Edinburgh were once a breeding ground for the black death.

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

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Home of an evil witch famous within southern folklore.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

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

A beautiful Victorian-era cemetery, complete with a miniature village.

A toxic ghost town sitting atop a massive coal fire.

A semi-scholarly approach to sex.

Enormous lake at the bottom of a unique cave system.

The fairy tale castle of the "fairy-tale king."

Resting place of Hollywood's immortals is also site of summer film screenings.

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

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

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

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

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

Try not to get slimed in Tribeca.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.