1. Revolutionary war-era cannon found fully loaded in 2013

This cannon was used on a British ship which sank  in the East River. After an anonymous donation in 1865, it was installed at Fort Clinton in 1905 where it remained on public display until 1996 when the Central Park Conservancy brought it indoors to protect it from vandalism. In 2013, however, workers from the Central Park Conservancy, while trying to refurbish and clean the cannon, found it to be still active — fully loaded with 800 grams of live gunpowder, cotton wadding and a cannon ball.

The gun powder has since been removed, and the cannon is now reinstalled in Fort Clinton, at 107th Street, close to 5th Avenue.