Cumberland Island is the southernmost and largest of Georgia's barrier islands, accessible only by ferry from St. Marys. Most of the island is National Seashore managed by the National Park Service, and it has been kept intentionally undeveloped. There are no roads open to the public, no cars, and no shops.
The island stretches about 18 miles long and up to 3 miles wide, with a white sandy beach along its entire eastern shore. The interior has maritime forest, freshwater ponds, and salt marshes. Wildlife is abundant — wild horses (feral descendants of horses brought by settlers), white-tailed deer, wild turkeys, armadillos, and alligators are commonly seen.
The Dungeness ruins at the south end are the main historic feature — a haunting complex of burned Carnegie mansion, overgrown formal gardens, and wild horses grazing where the ballrooms once stood. Plum Orchard, a grand 1898 Carnegie mansion in the middle of the island, is occasionally open for National Park Service tours. The tiny First African Baptist Church at the Settlement — where John F. Kennedy Jr. married Carolyn Bessette in 1996 in a ceremony so secret no press were present — draws visitors who want to see the place for themselves.
Camping is available at designated sites (reservations via recreation.gov required well in advance), and a single inn, Greyfield, provides upscale accommodation. Day visitors must take the ferry and are limited to 300 per day — the island's appeal is its near-wilderness character, and the limit protects it.