The secret city built by the Manhattan Project.

More than five miles of underground passageways.

Visit this playground of waterfalls, caves and sinkholes.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

All that's left of the quintessential "cabin in the woods."

Home of an evil witch famous within southern folklore.

Enormous lake at the bottom of a unique cave system.

A modernist landscape of water and sci-fi concrete.

The first ever diner included on the National Register of Historic Places is famous for its custard French toast.

Only a shrine remains at the site of the catastrophic nightclub inferno that killed 100 Great White fans.

A 19th century library favored by Edgar Allan Poe and H.P. Lovecraft, known by locals as "the Ath."

A secluded hilltop monument marks the final resting place of Lucy, Presidio Park's beloved white deer.

Nature and art meet in this curvy creation

A medical facility that has been kept frozen in time.

A modern-day wunderkammer dedicated to Indianapolis history, Afrofuturism, and musical vibrations.

A mega theme park-wax museum mélange containing all things biblical.

Human skulls and a stuffed goat made into a rocking chair can be found at this strange little store.

Remarkably realistic Florida shoal bass "swim" inside this large globoid sculpture.

Home to a giant switchblade and one of the world's largest collections of pocket knives, this museum is a cut above the rest.

Hundreds of skulls and bones at the largest skeleton museum in the country.

A museum preserving one company’s history of preserving food.

After the attack on Pearl Harbor, rocks and fossils from every U.S. state were collected into a pyramid of national unity.

A decidedly out of place statue memorializes the Blues Brothers characters at this water bottling plant.