Go Beneath the Black Hills, where wonder runs deep! Black Hills Caverns is a hidden world beneath the surface, where ancient formations and underground wonders are waiting to be discovered! Get your Crystal Tour, a 1/2 hour, 1,500-foot tour venturing through the cave through illuminated passageways and towering caverns filled with rare crystal formations, twisting limestone tunnels, and breathtaking natural sculptures carved by time. Scientists believe nature began to craft the Black Hills Caverns six million years ago! The Caverns are unique for more than their age and beauty; they are among a very small number of mineral caves in the world!