Rainbow Springs is Florida's fourth-largest spring system, pumping out roughly 400-600 million gallons of crystal-clear water every day. Unlike most Florida springs, there's no single boil here — the water rises from dozens of vents scattered along the headwaters, giving the river its famously even, glass-like clarity. People have been drawn to this water for over 10,000 years, and in the mid-1900s it was one of Florida's classic roadside attractions, complete with glass-bottom boats and man-made waterfalls you can still see in the park today. Now a state park, it protects the headwaters of the Rainbow River, a designated aquatic preserve. Keep your eyes out for turtles, otters, anhingas, and dozens of fish species thriving in the 72-degree water that stays the same temperature year-round.