Star Trek Expanded Universe

Starbase 23 was a United Federation of Planets Starfleet facility active in the 23rd and 24th centuries, located near both Klingon and Romulan territories. (TNG: "Suspicions") It was the nearest Federation base to the Arachnae Nova but still quite distant from it. (TAS: "The Counter-Clock Incident")

In the mid-2280s, the base's commanding officer was Commodore Antonia M. Niccomachi. (FASA RPG: Return to Axanar)

A G-class station (The Starfleet Museum), the starbase was a major repair facility. It was here that USS Justice was repaired following a disastrous collision with an asteroid in 2294. (Tales of the Seventh Fleet)

In the 2370s, Starfleet relocated Starbase 23 to the Talrath system, in orbit of Talrath IV. (Federation Gaming Network)