The Iffrig Building

Historical marker location:

103 Main St, St. Peters, Missouri

( Marker is at the intersection of Main Street (State Highway C) and National Street, on the right when traveling west on Main Street.)

Marker installed: 1985

The town of Bonne Terre, Missouri, has the largest underground lake in the United States. The Bonne Terre Mine was once one of the world's largest lead mines, but is now a popular scuba diving destination.