Blue Springs: Over one hundred million gallons of water pump through Blue Springs each day. The force is quite noticeable as it runs up the limestone walls, which resemble the image of a human rib cage. It's one of 33 magnitude-one springs scattered throughout Florida, which means on average it discharges 100 cubic feet of water per second. On the surface, it's a safe place for weekend warriors and tourists to cool off from the scorching heat. But at the bottom, it becomes cold and dark, creating a sense of euphoria you can only experience when you're isolated 70 feet underwater.