Enormous lake at the bottom of a unique cave system.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

Venue for strange sideshow displays and musical acts.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

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

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

Shop selling 500 flavors of soda has something for everyone.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

A semi-scholarly approach to sex.

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

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

A layered tribute to the work of mosaicist Isaiah Zagar.

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

A bizarre house filled with an astounding array of collections.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.