Cayo Costa State Park (north of Captiva, 941/964-0375, www.floridastateparks.org/cayocosta, 8 a.m.–sunset daily, $1) is only accessible by private boat or via the Tropic Star Ferry (13921 Waterfront Dr., Pineland, 239/283-0015, www.tropicstarcruises.com, departures 9:30 a.m., 2 p.m. daily, returns 1 p.m., 3 p.m. daily, round-trip $25), which departs from the Pineland Marina, about 26 miles (an hour’s drive) west of Fort Myers.

There are nine miles of beautiful white-sand beaches at the park, and snorkeling is fantastic just off-shore. There are 30 tent campsites ($35 per person) and 12 cabins that are nearly impossible to reserve, given the park’s popularity, but the entire island is incredibly rustic, and facilities are limited to a few public restrooms, outdoor showers, and a tiny concession stand that sells insect repellent and sunscreen.

In addition to beachcombing on the impossibly soft and sugary sand, visitors to Cayo Costa can also explore more than five miles of hiking trails that wind through hardwood hammocks and mangrove swamps.