In 2364, Relva VII hosted a Starfleet Academy entrance test for aspiring cadets. The successful cadet would gain entrance to the main branch of the Academy on Earth. In that year, Wesley Crusher, along with three other Academy hopefuls, Mordock, T'Shanik, and Oliana Mirren, took the Starfleet Academy entrance exam. One of the main tests on the exam was the psych test. Out of the four candidates, Mordock was chosen to enter the Academy. (TNG: "Coming of Age")
According to Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), the Relva system was located in the Beta Quadrant. This was a binary system with a K-class star and a M-class star. In the late 24th century, it was a Federation system.
The Federation Relva VII outpost
The exterior view of the Federation facility was a matte painting that was originally done by Dan Curry, prior to him becoming visual effects supervisor on Star Trek: The Next Generation, for Universal Studios' science fiction television series Buck Rogers in the 25th Century, where it appeared as the Aldebaran II spaceport in the 1979 first season two-part episode "The Plot to Kill a City", reused as the Zantia spaceport for the later, same season episode "Planet of the Amazon Women" (incidentally, co-written by DC Fontana).  It somehow became available for use for Paramount Television in The Next Generation where newly shot footage of the painting was only slightly modified in post-production by original creator Curry for its appearance as the Federation facility, among others by adding the Starfleet symbols on the dome. (Star Trek Encyclopedia (3rd ed., p. 405)) The painting was subsequently retained by Curry, as part of his personal collection. (TNG Season 6 DVD-special feature, "Departmental Briefing Year Six - Profile: Dan Curry")