Illinois Caverns State Natural Area State Park

(Illinois)

Illinois Caverns is a state natural area in the New Design Precinct of Monroe County, Illinois. It features Illinois Caverns which is alternatively known as Mammoth Cave of Illinois. Illinois Caverns is the second-largest cave in Illinois and has more than 9.6 km of passages. The cave has a constant temperature of 58 °F (14 °C), and portions flood during wet weather. Passages can be 20 feet (6.1 m) high and just as wide. It is located off Illinois Route 3, south of Waterloo, near the unincorporated community of Burksville.