IDH is correct, of course, but also slyly humorous.

According to river experts, whomever they may be, say the Hudson River is indeed a river as it has a fresh water source in the Adirondacks. It also has a school named after it, which of course has nothing to do with fish or bad teachers, but were landscape artists enthralled with romanticism.

I would add the Museum of Art and Design, if you have not been there.

http://www.madmuseum.org/visit

>>That should be spearing eels n the East Estuary.

Self guided walking tours all over the city
Walkingoffthebigapple.com

Guided tours
Freetoursbyfoot.com

Go see the Xmas lights in Dyker Heights Brooklyn either on your own or with
Asliceofbrooklyn.com

Speaking of a slice, they ( site above) do pizza tours in Brooklyn or
Scottspizzatours.com
In Manhattan

Go to one of the smaller museums. The Cooper Hewitt recently re-opened after a big renovation.
Frick.org is another or go to the Neue Gallery ( watch the movie "Woman in Gold" about the Klimpt painting that's housed there)

Merchant House is another.