Starbase 29

From Memory Alpha, the free Star Trek reference

Starbase 29 was a Starfleet starbase commanded by Admiral Budrow. It was mentioned in a delusion suffered by Commander Riker while under neuro-somatic interrogation during a mission to Tilonus IV. (TNG: "Frame of Mind")

In non-canon sources, Starbase 29 was mentioned as a 2280s USS Enterprise-A stopover in the DC TOS volume 2 #19 comic book, "Once a Hero...".