Gavrinis Slabs Material Notes, correspondence and photographs relating to Galton's interest in the Gavrinis slabs [also written Gavr'inis or Gavriniz], which are decorated slabs from the Gavrinis passage tomb, part of a megalithic monument on the island of Gavrinis off the coast of Northern France. Some of the slabs that line the walls of the passage are decorated in a distinctive pattern of loops and whorls. 1894