This peaceful 1260-acre park is graced with nature trails, swimming beaches and wildlife, including foxes, coyotes, snakes, seabirds and alligators (fear not: gators live in freshwater, and the swimming areas – including the kiddie pool's 4ft-deep water, near the jetties – are in the ocean). You can still see the circular cannon platforms from when this area was used as a military reservation during WWII; look for them on the beach near the jetties.
Excellent waterfront campsites are available year-round for $28.