Nyria III was, according to Dammar, the inhabited third planet in the Nyrian system. It allegedly contained a Nyrian colony.

Doctor Rislan claimed that strange graviton fluctuations had been detected near the colony. (VOY: "Displaced")

This planet was only mentioned in dialogue.
The Star Trek Encyclopedia (4th ed., vol. 2, p. 93) described Nyria III as a class M planet with a very warm, arid climate and a much lower daytime light level than Earth.