Three Sisters Springs is a unique and critical natural warm-water refuge for the endangered Florida Manatee. The springs, with their constant 72 degree Fahrenheit water, provide essential warm water refuge for the manatees that aggregate there in the winter months. Located in the heart of Crystal River, FL, Three Sisters Springs is a complex of three springs consisting of vents, sand boils and clean spring water that help feed Kings Bay, the headwaters of the Crystal River. Last winter the cold weather drove ?nearly 500 manatees into Three Sisters for thermal refuge and our visitors had an exceptional opportunity to watch these majestic mermaids.