|There is more information available on this subject at Argyre Planitia on the English Wikipedia.|
Argyre Planitia is a plain located in the Argyre Impact Basin in the southern highlands of Mars. Its name comes from a map produced by Giovanni Schiaparelli in 1877; it refers to Argyre, a mythical island of silver in Greek mythology.
During the Interplanetary War, this area fell under control of the Koslovics in 2160. In 2163, the Argyre Planitia Campaign was fought here, resulting in a UN victory. This is of note, as it was the first deployment of Marines outside of Earth, and thus, the first official conflict of the UNSC.