DOI Office of Everglades Restoration Initiatives, The Everglades is recognized both nationally and internationally as one of the world's most unique natural and cultural resources. Encompassing nearly 18,000 square miles of the southern third of the Florida peninsula the Everglades and the greater Everglades ecosystem (spanning from the Kissimmee River basin north of Lake Okeechobee all the way south to Florida Bay) are also the focus of the world's largest intergovernmental watershed restoration effort.