The Woodville Karst Plain is a 450 sqmi karst area that runs from Tallahassee, Florida, U.S. to the Gulf of Mexico separated by the Cody Scarp. This karst plain contains the Wakulla-Leon Sinks Cave System, the longest surveyed underwater cave in the United States, extending 32 mi and ranking #57 among the top 100 longest caves in the world. The plain is home to five of the 27 reported species of troglobites in Florida and South Georgia including Woodville Karst cave crayfish and Swimming Florida cave isopod. Also of interest are the Leon Sinks.

Wakulla-Leon Sinks Cave System

Wakulla cave consists of a dendritic network of conduits of which 12 mi have been surveyed and mapped. The conduits are characterized as long tubes with diameter and depth being consistent (300 ft depth); however, joining tubes can be divided by larger chambers of varying geometries. The largest conduit trends south from the spring/cave entrance for over 3.8 mi. Four secondary conduits, including Leon Sinks intersect the main conduit. Most of these secondary conduits have been fully explored. On Dec 15, 2007, the connection between the Wakulla cave system and Leon Sinks cave system was made by members of the Woodville Karst Plain Project to establish the Wakulla-Leon Sinks Cave System. This connection established it as the longest underwater cave in the United States and the sixth largest in the world at a total of 32 mi of surveyed passages.