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

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

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

A dilapidated dock tells the story of Titanic's missed arrival.

Long-forgotten artifacts give incredible insight into New York's most glamorous hotel.

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

A crumbling hospital from the 1850s on Roosevelt Island.

A mysterious air force base built to resemble a Long Island fishing village.

These etchings reveal the history of a long-gone quarantine site.

A tiny islet just off Long Island offers a wealth of infectious curiosities.

This picturesque Victorian ghost town was once a thriving mill community.

The mysterious headstone of an unidentified bank robber was seen visited, every year, by a woman in black.

A take-out restaurant that only serves cuisine from countries with which the United States is in conflict.

Hundreds of protractors affixed to surfaces all over the city.

There aren't too many operational funiculars around, but Pittsburgh has two!

This park contains a number of standing stones meant to heal and inspire.

This abandoned Poconos resort is haunted by a history of kitschy romance and a violent fugitive.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Collection of trolley cars in the woods represent one man's attempt to preserve transportation history.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

Mysterious rocks that ring musically when struck.