Federation map showing the position of Outpost 2 in relation to Romulus and the Romulan Neutral Zone
Outpost 2 was one of a series of Earth Outpost Stations located in Sector Z-6 along the Federation side of the Romulan Neutral Zone.
In 2267, the Federation lost contact with the base. It was determined, by the USS Enterprise, that the station was destroyed by an unknown vessel that was later discovered to be a Romulan Bird-of-Prey. (TOS: "Balance of Terror")
Location
According to the Star Trek: Star Charts, this outpost was located in the Beta Quadrant, and was established in 2060. This outpost was the first encountered by the unnamed Romulan bird-of-prey in 2266. (pg. 66)