From economic backbone of a community to deadly diving hole, these former stone quarries are now a park for rock climbers and graffiti artists.

Bizarre Cavern.

The mummified relics of an American missionary.

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

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

The boulder on which Alexander Hamilton laid his head as he died can still be visited on the New Jersey coast.

This otherwise innocuous bodega was once the headquarters of the most feared assassin's guild in American history.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

This seemingly unremarkable boulder is said to bear the hoofprint of the devil himself.

A heartbreaking monument showing the last morning in the life of Jane Griffith.

This study room in the New York Public Library saw the creation of one of contemporary America's greatest traitors.

A curious friendship between two inanimate ladies.

Nondescript elevator doors open to reveal a stunning, surreal world.

Even Henry David Thoreau found this glacial pothole irresistible.

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

An engraved boulder marks the spot where Patsy Cline's life ended in a plane crash.

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

New York's oldest magic store.

The remains of a 19th century spring, and the site of an infamous unsolved murder.

Built as a home for the Union Porcelain magnate in 1867, now the Greenpoint Reformed Church and home to a ceramic mystery.

Unlock the secrets of the conjuring arts.

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

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

The soulless eyes of 82 bronze children stare on forever in remembrance of a horrifying World War II massacre.