This leafy estate is worth $18 million and is so grand it has two mailing addresses.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

The site of the climactic scene from the classic horror film is now a historic landmark.

This historic building housed the surviving crew members of the Titanic, who were left destitute after the wreck.

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

Where now stands a 42-story condominium tower of marble, glass and steel was once the central market of New York’s slave trade.

This curved Manhattan building was built to house the opulence of John D. Rockefeller's oil empire.

The most confusing clock in New York.

A Manhattan Episcopal church with an eerie underground crypt.

A posh members-only club with a literally dramatic history.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

From scholastic to sepulchral - now under reconstruction.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

One of only two commuter aerial tramways in the United States.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

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

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A crumbling hospital from the 1850s on Roosevelt Island.

Dozens of lights dangle from the branches of what may be the brightest tree in Los Angeles.

The so-called "Statue of Liberty of Los Angeles" is on a one mutant mission to keep L.A. weird.

An increasingly eccentric apartment building, topped with winged beasties.