Maxia Zeta III

Maxia Zeta III was the uninhabited third planet of the Maxia Zeta system. This planet was located in the Maxia sector, Alpha Quadrant, and, like the fourth planet, was positioned inside the habitable zone of the system. Because of its location in the zone, Captain Jean-Luc Picard believed this planet could be a candidate for terraforming.

In 2364, the orbital path and size of this planet were displayed in a map of Maxia Zeta's inner system. (TNG: "The Battle", display graphic)

This planet was only mentioned in writing.
This planet's quadrant of origin was inferred based on the position of its star system as seen in the star chart appearing in the Star Trek: Picard episode "Maps and Legends".