Mercer Caverns were discovered on September 1, 1885, by Walter J. Mercer, who, while resting at this site, noticed movement of grass near a small hole. After enlarging the opening, he ascended into extensive caverns containing varieties of fantastic crystalline formations. Public tours began on September 12, 1885. In 1900, a display of the rare Aragonite Flos Ferri was awarded the Grand Prize at the Paris World's Fair. The site was recognized by the State of California as a Point of Historical Interest on August 2, 1985.