A 19th century library favored by Edgar Allan Poe and H.P. Lovecraft, known by locals as "the Ath."

Early prototype for Frank Lloyd Wright's Guggenheim.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

The remains of a ruined mansion memorialize the 1906 earthquake.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

A psychedelic labyrinth on the San Francisco bay.

From this desk Al Hirschfeld drew his influential caricatures of the 20th century's Broadway stars.

New York City's first Modernist house.

Currently housing a corporate bank branch this building at the southern tip of Manhattan was once the gateway to luxury vacationing.

Amid the marketing blitz of modern Times Square is an elegant holdover from its showbiz glory days.

There are owls with glowing eyes in Herald Square.

In the back of a nondescript sports bar is a museum-worthy mural by legendary cartoonists.

A crumbling staircase in upper Manhattan is all that remains of one of the most important sites in sports history.

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

This abandoned caretaker's apartment is one of 13 left in the New York Public Library system.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

Hidden in one of New York's oldest subway stations is the final remnant of the site of the bizarre Shakespeare Riots.

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

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

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

A gas station and a state sign commemorating the most famous claims of extraterrestrial abduction.