This haunting monument honors the victims of 9/11.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

The graffitied ruins stand hidden within the Pennsylvania woods.

Abandoned blast furnaces are an enduring reminder of Scranton's once booming iron business.

Home to items never before seen by the public.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

All you ever needed or wanted to know about America's favorite whiskey, but not a drop to drink.

Elvis's own personal tropical hideaway.

This replica of the Greek structure is in the heart of Nashville.

A historic freight system that found the true gold rush is in tourism.

The only surviving fragment of the lost Narragansett Pier Casino.

Ships still use this historic lighthouse to navigate dangerous, island waters.

Every equinox this Maya pyramid puts on a spooky ancient light show.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

One of the world’s oldest surviving convict prisons, once the scene of daring escapes and riots.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.

Yo, Adrian!

The world’s first penitentiary, meant to be humane, drove men insane.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This elaborate towering structure was once famed for its revolutionary height.

A stone arch leads to a cavernous 1930s spring house tucked away in the Pennsylvania woods.

These disused steel furnaces are now haunting ruins that may one day be a national park.