Earth Outpost 4

Earth Outpost 4 was one of several facilities monitoring the Romulan Neutral Zone.

Four facilities -- Earth Outposts 2, 3, 4 and 8 -- were destroyed on stardate 1709.2 by a single Romulan bird of prey testing the Federation's military strength. 

Earth Outpost 4 was apparently replaced. 20 years later, USS Konkordium was called to act as backup to USS Avenger during a standoff at Earth Outpost 4. (: "By Honor Bound")