Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

The eccentric mansion of one of the most popular horror authors of modern times.

A particularly creepy abandoned hospital that sparks interest for lovers of the supernatural.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

A clear blue swimming hole with hidden caves, still unexplored.

An abandoned castle owned and ignored by Masons carries a cursed history.

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

A religious-themed park filled with folk art to bring biblical stories to life that fell into disrepair and now being restored.

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

A museum dedicated to the alleged Roswell Incident.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

Quite simply the largest tree in the world (by volume).

A whimsical village of unique treehouses resides in a Washington forest.

Tour the sci-fi-esque reality of governmental disease management.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

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

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

An acoustic anomaly with a mysterious cause.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

Bigfoot prints, Feejee mermaids, and haunted dolls on display in a tiny North Carolina town.

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

A modernist landscape of water and sci-fi concrete.

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