Leon Sinks Geological Area is a karst landscape on the Woodville Karst Plain in southern and southwestern Leon County, Florida, where wet and dry sinkholes connect through underwater passages above the Upper Floridan Aquifer. Its defining feature is the Wakulla-Leon Sinks cave system, linked to Wakulla Springs through one of the world’s most extensive submerged cave networks. In 2007, the completed connection between the Wakulla and Leon Sinks systems created a surveyed network of 31.99 miles, then the longest underwater cave in the United States. Because this highly permeable aquifer is vulnerable to pollution, mapping and conservation have gone together to protect its waters and distinctive species.