Located in southeastern Lee County and northwestern Collier County, Corkscrew Swamp Sanctuary is one of the most significant natural areas in Florida, containing the largest virgin cypress swamp remaining in North America. The Corkscrew Regional Ecosystem Watershed Project was designed to further protect the Sanctuary by purchasing surrounding habitats, including a direct link to conservation areas to the south. Corkscrew Swamp receives 100,000 recreationists annually and contains an environmental education center for about 6000 schoolchildren each year.

In October 2009, Corkscrew Corkscrew Swamp was designated a Ramsar Wetland of International Importance, and an official designation ceremony was recently held in February 2010.

Corkscrew Swamp Sanctuary contains what often is the nation's largest Wood Stork rookery, although nesting success (which is dependent on local water levels) is extremely variable. The colony has been monitored annually since 1958. The Sanctuary also supports a diversity of Neotropical migrants, large numbers of wintering landbirds, and the third-largest Swallow-tailed Kite roost in the United States. Diversity of Corkscrew Swamp Sanctuary is 218 native species; CREW Wildlife and Environmental Area added only one exotic species to the overall list.