The oldest Dutch colonial stone house in New York City is a hidden gem on the border of Brooklyn and Queens.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

This forlorn park is the result of a failed investment turned tax dodge.

This once-grand marvel of engineering is now 41 miles of scenic hiking trail.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

A living archive of urban activism and space reclaimed.

Small monoliths of several varieties of stone sit alongside a wooded path in the Bronx.

Surrounded by low rise buildings and partially converted into an auto body shop, this marble archway is the only vestige of a forgotten Manhattan estate.

Manhattan and the Bronx have been playing tug-of-war over this former island neighborhood for more than a century.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

An eccentric home in Sicily turns heads on a regular basis.

Italian cave with exceptional acoustics and an unsavory history.

An artist's cute bronze subway sculptures belie his violent artistic past.

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.

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

Commemorating the spot where the famous scientist fed his pigeons.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A very classy 1920s-era bar right in Grand Central Station.

Visit the monolithic tomb of America's most famous general.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.