The two large springs featured here the Ichetucknee Headspring and Blue Hole Spring (also known as Jug Spring) are located within Ichetucknee Springs State Park. They and several more named and un-named springs yield 233 million gallons of crystal-clear, cool water to form the Ichetucknee River. The second-magnitude Headspring was declared a National Natural Landmark in 1972. Blue Hole, a first-magnitude spring, is about 1800 feet below the Headspring and boasts a powerfully flowing vent that descends 32 feet before extending horizontally into a cavern and cave system.