New York hidden gems

[squashyhat]

I'm thinking of doing a solo trip to New York next spring. I love the city and have been several times before, so done the main tourist sights (Empire State, Ellis Island, Top of the Rock - which I will probably do again as the view is so great - bike ride in Central Park, walked the High Line etc) The 9/11 memorial wasn't open when I last went so I will do that, and see a show on Broadway, but are there any other less obvious sights/visits I shouldn't miss?

Thanks so much!
Expecting a couple of rainy days, out of only 4 days there, but hey ho, what can you do!
Will report back on our faves.

Chelsea Market is great chelseamarket.com/ and there are some great shops in the adjoining streets which go down to the Hudson - lovely view of the Statue of Liberty. The Whitney Museum is there too - excellent views from the rooftop cafe.