Verdanis was an inhabited planet located ten days away from Terra 10, and the star Cepheus. It was described by James T. Kirk as "very beautiful, much like Earth" .
In 2269, the USS Enterprise transplanted the Terratin colony from the dying Terra 10 to a fertile and well watered plain on Verdanis. (TAS: "The Terratin Incident")
This planet was only mentioned in dialogue.
According to Star Trek: Star Charts ("United Federation of Planets I", "United Federation of Planets II"), the Verdanis system was located in the Alpha Quadrant. The system's primary was a G-class star.