Starbase 371

From Memory Alpha, the free Star Trek reference

Starbase 371 is a Federation starbase administered by Starfleet.

After a part of the Defiant crew helped a Starfleet garrison in defending AR-558 against Jem'Hadar attacks, the wounded from both the crew (including Nog) and the garrison were transported to the hospital at this starbase. (DS9: "The Siege of AR-558")