The Okefenokee Swamp is a shallow, 438,000-acre (1,770 km²), peat-filled wetland straddling the Georgia–Florida border in the United States. A majority of the swamp is protected by the Okefenokee National Wildlife Refuge and the Okefenokee Wilderness. The Okefenokee Swamp is considered to be one of the Seven Natural Wonders of Georgia. The Okefenokee is the largest "blackwater" swamp in North America.