To have the best lunches like a 'fried peanut butter sandwich', lounge or book a room for a few days in the heart of the city, visit 'The Ace Hotel'. Ease down in the couches, order a Brooklyn Beer and relax. A great place to meet up.
Apart from Dia Beacon, in Beacon (upstate New York about an hour away from Grand Central Station) and also the Judd Foundation in Soho, this institution is absolutely one of my favourite places to visit and it is located in Long Island City, Queens. It showcases sculpture in the broadest sense and has an incredible building that used to be a workshop that refurbished and fixed subway cars. It has been running since 1928 and when you visit you will definitely see why that is.
My friends, Dee & Ricky, recently opened up their own restaurant at the ripe age of 24 in the Clinton Hill neighborhood. I stop in here every now and then for the roti. Also, there's a really cool (Nigeria-owned) sandwich & smoothie spot next door that is not pictured.
An hour away from NYC, there lies a summer camp on a pristine lake which was abandoned 15 years ago. I cant tell you where this is, but some research can lead you to the right place.