Salt marshes are to your right. The mouth of a river is to your left. Calm water is straight ahead. Salty water splashes over the side of the boat. Seagulls squawk overhead. And the day’s expected high temperature was already exceeded due to the bright, midday sun. You roll up your pant legs and try to find the hat you thought you’d thrown in your carry-on bag. At least you have your sunglasses.

You’re on the Lucy R. Ferguson, passing St. Marys River, on your way across Cumberland Sound. Georgia’s Sea Islands are your destination. Cumberland Island, specifically. It’s the largest and the southernmost of Georgia’s barrier islands. The 18-mile-long island was once home to Native Americans, Spanish missionaries, African-American slaves, and wealthy industrialists. Now, it’s the Cumberland Island National Seashore, a wild and undeveloped area that limits the number of daily visitors. No worries. You booked one of the few rooms on the island.

Your room is at the Greyfield Inn. The grand old mansion is from a bygone era. It’s full of Tiffany lamps, Asian rugs, and family heirlooms. The Carnegies—yes, those Carnegies—built the mansion in 1900 for their daughter, whose own daughter turned it into an inn in the 1960s. Not much has changed in the past 50 years. A big Southern breakfast starts the day. Rocking chairs and swinging benches fill the porch. A picnic lunch is packed within a red-checkered napkin. Milk and cookies are always available for a late-afternoon snack. Drinks come from the “Honest John” bar. And jackets are expected for dinner. The rest of the day, you are free to explore.

Despite, or perhaps because of, the lack of development, there’s a lot to explore by foot or bike. Start south, in Dungeness, an area once home to stately sugar cane and cotton plantations. The last estate burned down in the 1950s. Feral horses graze in the open field next to the ruins. The Greene-Miller Cemetery, with the tomb of a Revolutionary War general, is a short walk away. Marshes are beyond the graveyard. You never know what you might see there. American alligators sunning on the creek banks. Fiddler crabs, oysters, and ducks in the water. Wood Storks and egrets fishing. Or a flock of swallows heading north overhead.

Head north yourself, along Grand Avenue. The unpaved road is lined with a canopy of moss-shrouded live oaks. Wild turkeys breed in the open fields. Fawns try to keep up with their mothers. You pedal toward Brickhill Bluff to see manatees and dolphins in the water. Eventually, you reach “the Settlement,” a segregated area created for African-American workers in the 1890s. The little First African Baptist Church is one of the few surviving buildings from this period. It’s where John F. Kennedy, Jr. married Carolyn Bessette in 1996. A nine-banded armadillo is guarding the door when you arrive.

You’re hot and sweaty, so it’s time for the beach. It’s long, wild, and lined with dunes. Search for shark teeth, disc clams, and heart cockles that washed ashore during winter storms. Kayak just beyond the waves. Go fishing along the shore or shrimping in the marsh. Find a sand dollar at the edge of the water. And hunt for some shade in the wooden gazebo. You have just enough time for a quick nap before you have to shower for dinner.