U Thant Island

U Thant Island did not exist until the final years of the nineteenth century. It emerged only as an accidental byproduct of a massive industrial project beneath the East River. As workers dug a shaft down through a dangerous granite outcropping known as Man o War Reef to create a tunnel for trolley cars, they deposited the massive amount of excavated rock and debris directly onto the reef. This debris accumulated until it rose above the surface of the water, leaving behind a small, man-made island that remains the smallest in the borough of Manhattan.