I think it takes place every Saturday morning to afternoon, vintage shopping while having a great view at the Manhattan skyline from the East River State park. You will find lots of vintage shops and warehouses around this area of Williamsburg.
Dumbo, which stands for 'Down Under the Manhattan Bridge Overpass,' is a neat neighborhood in Brooklyn that is at an awesome vantage point of Manhattan. There are cool rocks on the shore of Brooklyn Bridge Park that are fun to relax on and sneak alcoholic beverages.