In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

These WWII-era murals were initially booed as a libelous portrayal of the American dream but have survived multiple attempts to have them destroyed.

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

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

A popular tourist cave with a dark past.

One woman's Viking Castle on Lake Tahoe.

This historic California cemetery holds the bodies of veterans of both the Civil War and the Donner Party.

A watering hole where the options for seating include a bar, patio, or subterranean cave.

I Street Bridge is the heaviest swinging center bridge in the United States.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

The trials and tribulations of marking Poe's grave.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

Commemorating the spot where the famous scientist fed his pigeons.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Walk into the 19th century without leaving Brooklyn.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Twice a day one of these tragic bronze mariners drowns with the tide to remember all those the sea has taken.

This vacant church in the Financial District was once the heart of New York's first Syrian immigrant community.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Unrepaired walls from a 1920 anarchist bomb attack.