A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A wondrous old library overlooking the nation's capital.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

These eerie outliers of the lightning bug family glow a mysterious blue color.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

An unassuming secret door once led to a legendary watering hole.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

Historic funicular railway, believed to be the shortest railroad in the world.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

The private clubhouse for the members of the Academy of Magical Arts.

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

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

Home of an evil witch famous within southern folklore.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

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

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

Enormous lake at the bottom of a unique cave system.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

The inspiration for H.P. Lovecraft's horror stories and Batman's Arkham Asylum is now a condominium complex.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

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

Elevated freight railway turned wildly successful urban park.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.