An abandoned 19th century quarry in the middle of the woods, remade by unnamed wanderers into a massive series of rock thrones.

This locally-famous crevasse in New York State is icy all year round.

This sandstone gorge in New York State's Adirondack Mountains is home to waterfalls, flumes, and more.

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

Town full of spiritualists, some of whom are mediums, is still in full swing after 130 years.

Commemorating the spot where the famous scientist fed his pigeons.

For over 80 years, Mayan ruins stood proudly in a most unlikely location.

Nikola Tesla's former home contains an homage hidden from plain sight.

The former hotel where Tesla invented the radio.

Cryptic messages embedded in the New York City sidewalk.

An abandoned asylum where patients have been forgotten but their possessions remain.

A once grand hotel is being retaken by the wilderness it once capitalized on.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

The "Seinfeld" diner.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

A hands-on traveling collection of the innovative devices of yesteryear.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

Elevated freight railway turned wildly successful urban park.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

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

A terrific purveyor of natural history objects and curios.

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