Place your bets.
Never mind the seedy stigma. Belmont Park offers a sprawling, rubber-floored playground, a duck pond, and untold lessons in playing the odds (2150 Hempstead Turnpike, Elmont; from $3, under 12 free).
The surest way to keep a teen away from a spray can is for Mom or Dad to become a tagging enthusiast. Hire a guide through GraffTours.com to explain the finer points of downtown’s illicit art (adults $20, students $10).
Get good and filthy on a freegan garbage tour. About 30 members of the Freegan.info forum gather twice a month to forage for perfectly edible food items tossed by supermarkets. Check the site for dates and locations.
Sun in the buff.
Sandy Hook’s unspoiled, lifeguarded, “clothing optional” Gunnison Beach is perfect for an un-encumbered our-bodies-ourselves day away from civilization’s mores (Seastreak Ferry, adults $43, kids $16; seastreak.com).
Kayak on sludge.
The Gowanus Canal may be a Superfund site, but it’s also awesome. The Gowanus Dredgers Canoe Club holds free, self-guided paddles Saturday afternoons and Wednesday evenings (gowanuscanal.org).