Popham Beach State Park, Maine
I was in need of a beach day. Including a nap. Initially hesitant to visit such a popular beach (where there were sure to be lots of people), I ultimately decided to go to Popham Beach because I was assured by the Internet that it was a large beach where I could find a secluded spot and also because there is an island you can walk to at low tide. Well, there were a lot of people. But it was also a very long beach, and one that offered me both a nice quiet spot that was about ten minutes down the beach and a couple hours worth of exploring at low tide after a morning of relaxation. The only people I really ended up encountering that day were near the island when I went to check it out at low tide; most of the rest of the day I spent by myself, which suited me perfectly.