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

The boulder on which Alexander Hamilton laid his head as he died can still be visited on the New Jersey coast.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

From scholastic to sepulchral - now under reconstruction.

Visit the monolithic tomb of America's most famous general.

A Manhattan Episcopal church with an eerie underground crypt.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

World War II-era bunkers are hidden under the beaches of this picturesque park, which is still scattered with wartime watchtowers.

In 1787, a group of delegates met at this very spot to drink, be merry, and ratify the Constitution of the United States.

A scenic fort on the harbor protected Philadelphia from an attack that never came.

This splendid Versailles-inspired mansion has the largest French-style formal gardens in North America.

The ruins of an 18th-century mansion that was once named "Mistake" by the man who had it built.

This former tuberculosis treatment facility now stands at the center of a public park.

Home to the abandoned Tioronda Hat Works Factory, this park is a combination of woodlands and marshlands.

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

Now the final resting place of prominent artists and musicians, it was originally founded to separate the rich from the poor in death.

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

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

An enormous cat made of recycled wood scraps.

It's unclear what caused the fire that led to this opulent hotel's demise.

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

This Boy Scout retreat acted as "Friday the 13th"'s original Camp Crystal Lake.