The 28-foot granite map plots the locations of 40 theaters in New York City.

Beautiful mosaics cover the first stations opened on New York City's newest subway line.

A uniquely lettered street sign marks the corner where the iconic word game was invented.

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

This was one of the first (and last) university-built and operated nuclear reactors.

The first "Hall of Fame" in America was designed by legendary Gilded Age architect Stanford White for what was then the NYU uptown campus.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

The mummified relics of an American missionary.

Where now stands a 42-story condominium tower of marble, glass and steel was once the central market of New York’s slave trade.

The iconic Manhattan corner that was once the site of the Beastie Boys' fake clothing store.

Little Red Lighthouse under the George Washington Bridge.

Come for the pastrami, stay for the million-dollar art.

The site of the deadly Triangle Shirtwaist Factory Fire.

The notorious headquarters of a corrupt political machine.

Salute the leader of the proletariat.

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

Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

A good place to research the Freemasons, esoterica, occultism, and hermeticism.

Relics given to a Manhattan church to avoid seizure by the Italian government.

Touching mementoes from those who didn't make it back from World War I still hang in one of New York's oldest bars.

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

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.