Mermet Springs is in Metropolis, IL as soon as you cross out of KY on I-24. It is 3 hours North of Nashville, TN and is one of my favorite dive sites to visit.
Super Friendly staff, excellent amenities onsite, lots of attractions and training platforms underwater, along with a lot of large catfish and a large spoonbill fish population that run up to 6’ in length.
Depths run from 15’-120’ and the "special" attraction is the 727 airplane that was used in the movie U.S. Marshals.