Denius III was the third planet in the Denius system, which had once been in contact with the ancient Iconian civilization. In 2365, the Federation conducted an archaeological expedition on Denius III, headed by Dr. Ramsey. His team discovered an artifact of Iconian manufacture, and Ramsey allowed Captain Varley of the starship USS Yamato to conduct his own study on the device. The device contained a starfield, which allowed Varley to locate the planet Iconia. (TNG: "Contagion")