Sunday Afternoon Fun

Given the rainy weather we're having today, I was thinking about where to take my kids when the sun comes out again, maybe on a day like Tuesday when it's supposed to be partly sunny. With our town's relatively short commute of 28 minutes, I'm guessing many of us have some extra time to spend with our families on a free afternoon. What's the best local spot to take kids, or even a dog, on a nice day like that?