Xendi Starbase 9

Xendi Starbase 9 was a Federation starbase administered by Starfleet in the Alpha Quadrant. This facility was located within the Xendi Sabu star system in the Alpha Quadrant.

In 2364, the USS Enterprise-D arranged with this starbase to have a tug rendezvous in the Xendi Sabu system. The tug was to tow the USS Stargazer to Xendi Starbase 9 after it was returned to Starfleet by the Ferengi. (TNG: "The Battle")

The Stargazer was temporary stored at this starbase before a tug sent it to the Fleet Museum at Athan Prime, where it was restored and put on display in 2402. (PIC: "The Star Gazer" commemorative plaque; PIC: "The Bounty", "Vox", "The Last Generation")

This starbase was only mentioned in dialogue.
The quadrant of origin for this starbase was inferred based on nearness of the Xendi Sabu system to the Maxia system, which was located in the Alpha Quadrant as seen on Federation star charts, and that this starbase was in the Xendi Sabu system was inferred based on the fact that the Enterprise was doing a sub-warp tow of the Stargazer.
The Constellation-class Starfleet Technical Database article called Xendi Starbase 9 a "Federation contract repair base".