Time Out says
From June 18 through August 8, the Flatiron Public Plazas will be celebrating summer with educational and active free events. While most offerings are more geared for grown-ups, kids will love stopping by the North Plaza on Thursdays (11am to 7pm) for board games, giant Connect Four, and Corn Hole — on select days there will even be live music. The whole family can also celebrate the official start of the season with the Summer Solstice Sundial Event (June 20th), with a full day even that will include activities from the National Museum of Mathematics (MoMath). All ages.