Visitors to Salt Springs State Park are encouraged to literally put their two cents in Penny Rock.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Lines from a walking song are etched into a rock in Natural Bridge State Park.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

A 100-foot metal tower and swinging bridge that provides stunning views of mountains in five states.

More than 350 million years ago, western New York was covered in a vast sea. Today, you can dig up the remains of the plants and animals that lived there.

In paradise, feral pigs have claimed an island all to themselves.

The first and only carousel with a lineup entirely of insects.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

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

One of the world's few mounted blue whales, its jaws are hinged open allowing visitors to descend into a lounge.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

This grand gothic brewery has been pumping out suds for over a hundred years.

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

See wolves, coyotes, and arctic foxes in a natural environment smack in the middle of New York State.

These beautiful ruins deep in the Pennsylvania woods are thought to have been a ski lodge or a speakeasy, but no one really knows.

This small Catskills village has six independent bookstores and more bookshops than restaurants.

The former home of a disgraced local priest now hosts a mysterious secret supper club.

Some of the smallest works of art in existence.

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.

A hip bar decorated with walls of golden skulls.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

A partially hidden wall graffitied by spectators of the 1976 Bicentennial, recently rediscovered.

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