The Cavern of Screaming Skulls was a cave within volcanic Mount Octan, on Fondor's jungle-moon of Nallastia. Hidden deep within the cavern were the fabled Lost Stars of Nallastia, originally brought to the moon by founding colonial leader, the Margrave Octan. Obi-Wan Kenobi, with the help of the Skull Queen (the moon's ruling Margravine, Quenelle), recovered these ancient power gems in 23 BBY, in order to free the parents of Klay Firewell from the life-threatening energy-field of the megalithic Trinity Stones.