llinois Caverns is open to visitors with valid permits from Thursday through Saturday. The hours of operation are 8:30 a.m. to 3:30 p.m. No one is allowed to enter the cave after 2:30 p.m. Group size: Minimum of 4 persons. A group of 25 or more must preregister for permits prior to arrival. Youth groups require 1 adult leader for each 5 minors.

There is no admission charge, but guests are required to complete an application permit at the site office before entering the cave. Visitors are required to be in groups of four or more, have sturdy boots, a hard hat and three sources of light per person.

Illinois Caverns State Natural Area is a 120-acre preserve owned by the Illinois Department of Natural Resources. The main attraction of the site is an uninmproved wild cave with nearly three miles of walking-height passage. Located in karst-rich Monroe County, the area contains fields, woodlands, native grasses and a half-mile long prairie trail.