Mammoth Cave National Park - Kentucky 52,830.19 acres. With 392 miles of passageways mapped, Mammoth Cave is by far the world's longest cave system. Cave animals include eight bat species, Kentucky cave shrimp, Northern cavefish and cave salamanders. Above ground the park contains Green River, 70 miles of hiking trails, sinkholes and springs.
Kentucky's cave adventures are a truly unique experience and are a great option any time of the year. Search here to find out where you can start your cave adventure! Pictured: Carter Caves State Resort Park - Photo via Carter Caves Facebook page by Nicole Butler Towles.