The biggest lagoon in Florida is the Indian River Lagoon (IRL). It is a massive estuarine system that stretches for 156 miles along Florida’s Atlantic coast, running from the Ponce de Leon Inlet in Volusia County down to the Jupiter Inlet in Palm Beach County. It is actually composed of three distinct water bodies: the Mosquito Lagoon, the Banana River, and the Indian River. The IRL is not just significant for its size; it is also one of the most biodiverse estuaries in North America, serving as a vital habitat for more than 4,300 species of plants and animals, including manatees, dolphins, and sea turtles. Despite its ecological importance, the lagoon has faced significant environmental challenges in recent years, including nutrient runoff and harmful algal blooms. Conservation efforts are ongoing to preserve this massive waterway, which acts as a critical nursery for the Atlantic Ocean’s fish populations and a major hub for Florida’s recreational boating industry.