Outpost 23
Outpost 23 was a Federation outpost along the Romulan Neutral Zone. In 2367, it was the key outpost in Starfleet's defenses along the border and its location was a tightly guarded secret. 

In 2366, after receiving intelligence from a Romulan defector about a possible Romulan base at Nelvana III, this outpost received a warning from Starfleet Command. ()

In 2367, in a holoprogram created for William T. Riker by Barash on Alpha Onias III, Outpost 23 was supposedly no longer of strategic importance and was slated to be the site of final peace negotiations between the Federation and the Romulan Star Empire, an apparent ruse to reveal the location of the outpost. ()

de:Außenposten 23
fr:Avant-poste 23
it:Avamposto 23
nl:Buitenpost 23
Romulan Neutral Zone
Outposts