For kids in the Hamptons there are really only two kinds of days: ones you can go to the beach and ones you cannot.
Almost every public beach is kid-friendly here, but some have added attractions making them better choices, particulary for the younger set. Most of the bay beaches are safe and kid-friendly. In places protected from the ocean's waves, there are lifeguards at Gin Beach and South Lake Drive in Montauk, Abraham's Landing and Maidstone Park in Amagansett and Springs, Havens Beach in Sag Harbor, and Long Beach on the long causeway between North Haven and Noyac in Southampton. On the ocean, Ditch Plain in Montauk is a great family choice, with two or three concession trailers for snacks and expert lifeguards. There is a state park beach at Hither Hills in Montauk (on Old Montauk Highway) with lifeguards and a playground right behind the dunes. Parking is free after 4 p.m.
Atlantic Avenue in Amagansett and Main Beach in East Hampton are also top choices. Main Beach in particular, is walking distance from the village and has a shop with food and some sand-fun necessities. Hamptons Free Ride runs shuttle loops in its open-sided electric cars from the business district, something kids are sure to enjoy.
When the sun doesn't shine, indoor activities include climbing the Montauk Lighthouse for those 41 inches and taller or playing a round of miniature golf at Montauk's Puff 'n' Putt. In Amagansett, there is an interesting exhibit of whaling and fishing technology from days gone by at the East Hampton Town Marine Museum, which has a small playroom for kids with a killer ocean view. A volunteer-run boatbuilding shop occupies a building on the property; it's open Wednesday and Saturday until 2 p.m. to visitors. In East Hampton the Y.M.C.A.-RECenter sells day passes for its two pools.
Sag Harbor has its own Whaling Museum and the Goat on a Boat Puppet Theatre, which has inventive shows and playgroups for those under three or four. The South Fork Natural History Museum in Bridgehampton is a good stop for all ages and has some live animals on exhibit. Across the street from SoFo, as it's known, is the Children's Museum of the East End, with interactive exhibits, playgroups, and art workshops. The Parrish Art Museum in Water Mill has afternoon workshops for kids many days of the week. Farther afield, the Long Island Aquarium in Riverhead has plenty to see and do to make a trip worthwhile. Adults interesting in fishing will be awed by seeing huge striped bass in a replica creek swirling underfoot.
School playgrounds are open to the public when school is not in session. There is a great one at the Montauk School off Second House Road, and others in Amagansett and East Hampton Village. The Town of East Hampton Youth Park on Abraham's Path has skateboard ramps, a roller-hockey rink, track, basketball court, tennis courts, and an indoor playroom. Some funky, old bicycles, helmets, and other gear are available for loan. In Sag Harbor, kids really go for Mashashamuet Park, which has tennis courts, playground equipment, and wooden pretend trains and the like.
During the summer, there are number of special events that cater to kids and/or welcome them. These include the East Hampton Ladies Village Improvement Society fair in July and a celebration of books and reading (with bouncy castles, of course) hosted by the East Hampton Library, and an eye-opening one-day open house at the Byrd Hoffman Watermill Center with performances, crafts, and a Mr. Softee ice cream truck in August.
Drop-in programs, usually for a fee, are run year-round. There are choices at the Golden Eagle Art Supply shop in East Hampton Village, and also at Guild Hall. The libraries for the most part all have activities for kids and great online calendars. Main Beach Surf and Sport, Air and Speed in Montauk, and Flying Point Surf Shop give surfing lessons. Plaza Sports in Montauk, Khanh Sports, Flying Point, among others have all the beach gear kids will need. An outing on one of