Must sees on a visit to Cape Cod (preferably ones that won't be swamped by tourists)

In the summer, there will be tourists. Period. But crowds are less of an issue at my favorite spot to spend a day on the beach on the Cape: Chatham. The town is cute in a quaint-have-tea-with-grandma way. (None of the flamboyance of Provincetown or the suburban/tourist mess that's closer to the mainland.) It simply and perfectly matched my idea of what a New England seaside town should be. And the beach is great. There's a lighthouse, gulls and the full expanse of the Atlantic stretching out beyond the sandbars.