Large

Meramec Caverns

Saves: 8
Check-ins: 0
Formed from erosions of limestone deposits about 400 million years ago, the Meramec Caverns is a 4.6-mile cave system in the Ozarks. Rich in saltpeter, the cave was used by the Union forces to extract potassium nitrate for gunpowder during the Civil War. However, Confederate guerillas destroyed the saltpeter plant.