Bannerman Castle is located on a small island in the middle of the Hudson river, just south of Beacon. If you've taken Metro-North to Poughkeepsie, then you've seen it from the train. There is a lot of history if you are interested, but basically it's a rich guys fantasy come to life. Unfortunately, the rich guy wasn't an architect, so the structures aren't doing so good. It's a pretty train ride (about an hour and a half from NYC) and you are sure not going to see anything like it anywhere else!