13. Fort Tilden National Park
Built in 1917, Fort Tilden has a history in almost all of America’s greatest wars. It served as a munition house during World War I, a force for defense in World War II, and even as a storage facility for nuclear weapons during the Cold War. Now, however, the fort has been left to nature, which has quickly taken it over.
Officially gifted to the National Park Service in the 1970s, the fort now remains a shell of its former self. Thick layers of green cover almost every inch of the base, but this isn’t necessarily a bad thing. The silos and amphitheaters have been used for art installations, performances, and even a Hurricane Sandy benefit. This place that was once a piece of war is now a part of nature and one of the city’s most popular abandoned places.