Great National park/seashore facility. We're not talking the Grand Canyon here, but for its size this is a beautiful place. First things first... They have great public restrooms which, along 6A, can be hard come by. The visitor center has a small, but interesting museum, a number of kid-friendly interactive displays, and a gift shop with regionally appropriate offerings. There is a large Auditorium where they play a 15 minute movie describing the area. The front desk is manned by volunteer and paid rangers who are congenitally happy and helpful and they love interacting with kids and adults alike. What makes the park really shine, though, are the miles of walking trails that go around the Salt Pond and through the woods. They are all pretty flat, there are routes of different lengths, and you can get maps but it's pretty hard to get lost. If you have the legs for it, you can hike to the ocean. If you're a bit less brave they have shuttle busses or you can ride your bike on a beautiful paved bike path. The National seashore visitor center has scads of free parking and it's a great place to entertain (and exhaust) the kids. Costs nothing to go and enjoy so you can't beat the price. Cape Cod at its best. Go!