A stone arch leads to a cavernous 1930s spring house tucked away in the Pennsylvania woods.

Steepest flood safety railway in the entire world.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

The mortal remains of a Russian prince, priest and paranormal investigator who came to America in 1792.

A living maritime paradox still floats in the same lake where it was built and resurrected... or was it?

A natural gas leak provides a flickering flame beneath a waterfall.

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

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Step back in time on this preserved 1800s farm.

Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

Three and a half miles of cliffs, rocky beaches, Gilded Age mansions and 40 Steps to nowhere in particular.

A 60-room castle constructed by a horse-racing heir.

This Rhode Island mansion was a stand-in for the exteriors of Collinwood in the original "Dark Shadows" series.

Home of Philip Johnson, one of the 20th century's most influential architects.

137 graves holding New England's earliest residents.

This small-town Connecticut restaurant gives each diner a free book from its vast library.

Underground tunnels remain beneath this abandoned mental asylum.

An archival collection of over 2,200 case studies which includes human brain specimens and tumor specimens.

The intriguing personal collection of a professional demon-chaser.

A collection of haunted artifacts chronicles the career of the world's most famous paranormal investigators.

A centuries-old church stands as a testament to Boston's "father of architecture."

This classic red schoolhouse is said to have been where Mary and her little lamb went to school.

Last church of this militaristic WWII style.