 Since an Oriental inscribed cylindrical seal found at the palace can be dated 14th-13th centuries, the myth of Semele must be Mycenaean or earlier in origin.At the Alcyonian Lake near the prehistoric site of Lerna, Dionysus, guided by Prosymnus or Polymnus, descended to Tartarus to free his once-mortal mother.Annual rites took place there in classical times; Pausanias refuses to describe them.