I went to high school in the next town over from Paterson. I haven't been there in years but if I remember right, that's a big spot for wedding parties to take their pictures in front of.
But yeah, it was a big fad for 19th and early 20th century millionaires to build their own little faux castles. Some examples after the link:
http://mashable.com/2014/07/06/american-castles/#i4vH2TJ7IPqc