Why is there so much sandstone in Lincoln and why was a cave dug out of it in the 1860s? Nebraska Public Media producer Andy Hermann goes underground to file this report about Robber's Cave. Guests, in order of appearance: Joel Green, author, Robber’s Cave: Truths, Legends, Recollections; Cara Burberry, president, Nebraska Geological Society. Music: "Ghosts of Robber’s Cave" by Dorothy’s Dishes.