A Federation science space station, located in the Amargosa system.
In 2371, the observatory was attacked by Romulans looking for trilithium stolen by the Duras sisters: Klingons Lursa and B'Etor. Dr. Tolian Soran was a scientist aboard Amargosa. Soran used the station to further his plans to bring the Nexus energy ribbon to him, by launching a solar probe into the Amargosa sun.
Picard and the Enterprise-D were sent to investigate the Romulan attack, and rescued Soran. Soran beamed back to the observatory, where he took Geordi La Forge hostage, before firing his probe into the Amargosa sun. The probe caused a quantum implosion, and the resulting shockwave wiped out the observatory.