A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

This monument to a veteran of the Mexican-American War is one of only two in Manhattan that serve as an actual mausoleum.

A 19th-century politician who died after walking home in a blizzard is honored with this Manhattan statue.

The one-time office of the architectural firm that ushered in the Gilded Age is now a Club Monaco.

The rough and tumble president's childhood home displays the shirt he was once shot in and the speech that saved him.

Filled with history, this cemetery is maintained each summer by a few hungry goats.

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.

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

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

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

In its day this historic fort held 100 cannons pointed in almost every direction to protect New York.

Lie in a hammock where George Washington stood.

This evocative New Jersey statue memoralizes the Polish victims of a Soviet massacre.

On the Hudson resides one of the largest clocks in the world.

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

Once considered a marvel of engineering, this 107-mile canal played an integral role in building New York City.

A simple plaque remembers an act of WWI terrorism that obliterated an island and forever scarred the Statue of Liberty.

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

A playground inspired by differential calculus dangles from the ceiling of the Liberty Science Center.