Limestone caves with spectacular showcase chambers.

One of the largest, oldest, darkest, quietest motel rooms in the world.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

This plot of old-growth forest is the largest surviving remnant of New York City's original woodland.

An unrealized dream to wirelessly electrify the entire Earth.

The library of every book lover's dreams.

What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

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

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

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

Comprehensive gaming collection of over 30,000 electronic games and consoles.

Walk into the 19th century without leaving Brooklyn.

A Frankenstein blend of science and art allows one tree to produce 40 different types of stone fruit.

This interactive gallery makes you feel like you've stepped into a fantasy world filled with whimsical monsters.

Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.

Protecting the future of some of the rarest and most misunderstood mammals of North America.

A deteriorating 1990s Girl Scout camp in a beautiful lush park on Lake Ontario.

This old cement mine has been used as everything from a mushroom farm to a recording studio.

This former theme park in New York's Adirondack Mountains fell into ruin before being resurrected as a state-run campground

Find out what it sounds like when doves cry at Prince's recording studio estate turned museum.

This lab's maddening silence is good for business but bad for sanity.

An Escher-inspired library dedicated to the wonders of the human mind, yet closed to the public.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.