In the fictional Star Trek universe, where is the Starfleet Academy located?

The main campus of the Starfleet Academy is in San Francisco (technically in what is now Fort Baker, Calif. across the bay via the Golden Gate Bridge).

In the Star Trek universe, the academy is where recruits with aspirations of becoming Starfleet officers go to train.

The Academy's motto is "Ex astris, scientia" – "From the stars, knowledge." This is derived from the Apollo 13 motto "Ex luna, scientia" – "From the moon, knowledge." In turn, the Apollo 13 motto was inspired by "Ex scientia, tridens," the motto of the United States Naval Academy, meaning "From knowledge, seapower."

Citizens must obtain a letter of recommendation from a command-level officer in order to take the academy's entrance exam.

The academy is mentioned countless times throughout the various Star Trek television series and movies. In producer J.J. Abrams first film of the new Star Trek movie series (called Star Trek) the academy plays a major role as the backdrop for where the traditional characters -- James Kirk, Mr. Spock, Uhura, Dr. McCoy -- first meet. In that film, the exterior of the Oviatt Library on the campus California State University-Northridge was used to depict the academy.