Fort Tilden is a rarity in New York. It's quiet, abandoned, remote, and hard to reach--especially on public transit. The best route is to take the 2 or 5 subway to the last stop--Flatbush Ave. Then board the Q35 bus disembark as soon as the bus crosses the Marine Parkway Bridge over Jamaica Bay. From there, you can walk to Beach 169th Street and head into the park. The area is run by the National Parks and is open during daylight hours 7 days a week. It's a surreal and peaceful place. The initial walk is through an old military barracks and parade ground, still used by locals for the baseball field. But the best stuff is to head to the beach and into the dunes. There you'll find nature reclaiming the facilities that once protected New York City from German or Soviet attack. Houses and streets are covered in sand. Abandoned munitions sheds are covered in graffiti and surrounded by dune and scrub. And the enormous 16" gun casements loom dark and empty amongst the hills. Walk up the stairs to the top of the casements and you can see the 20 mile view back across the marshes, the homes of Brooklyn, and all the way to the towers of Manhattan.