The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

The famous boat that once ferried Bogart and Hepburn still floats in Key Largo after being abandoned for years.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

This block in downtown Brooklyn was a hotbed of antislavery activism along the Underground Railroad.

The ballpark in "Pigtown" where the Brooklyn Dodgers made their name was replaced with a huge apartment complex.

Where the Monitor was launched and ushered in the age of the "ironclads."

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

Etchings in a pile of boulders on the Long Island Sound are a monument to vanquished native peoples.

Fossilized sea bottom and lime quarry.

Once called Winthrop Park in 1889, home to a decidedly sexy tribute to the Monitor vs. Merrimac battle.

The front yard of an Upper East Side town house hides the last fragment of one of New York's most famous theatres.

Two mermen, eternally spitting into each other's mouths.

A drawbridge named for a potentially intersex Polish national who fought alongside George Washington during the American Revolution, and an example of "Pulaski Red".

The legendary court where emerging basketball players gain their street cred.

The "last holdout of the Confederacy” actually sat at the edge of the Canadian border.

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.

All that remains of one of the Civil War's more deadly POW camps is a simple flagstone.

The only surviving sidewalk clock in Brooklyn.

The humble fort that saved Washington.

The only remaining building in New York to see the inauguration of a president is being slowly overtaken by a grocery store.

While it now takes more than a dime to open an account this historic Brooklyn bank still displays the opulence of the gilded age in which it was built.

Rat sculptures try to infiltrate the Graybar Building in an architectural tribute to New York City's nautical history.

A gazebo that inspired the fifth episode of the "Twilight Zone" still stands in the creator's hometown

What remains of the simple red brick chapel where the women's rights movement began.