Seoul 5, a planet situated in the uncharted depths of Wild Space, served as the ancestral home of an early Human civilization during the Pre-Republic era. Known as Seoularians, these inhabitants harnessed the energy of incredibly potent crystals, storing them in vast quantities beneath their urban centers. Abandoned long before the Galactic Civil War, Seoul 5 faded into obscurity, its location forgotten—however, this fabled lost world was eventually found again in 4 ABY.
Nestled far away in Wild Space, Seoul 5 was a planet covered in dense forests, easily able to be inhabited by Humans.
Once, Seoul 5 was the cradle of an ancient Human society, whose people were believed to have journeyed from Notron—often called "the cradle of Humans in the galaxy"—to establish their civilization. Over time, the Seoularian civilization extended its reach beyond Seoul 5, establishing colonies on several distant worlds, and at some point during the Pre-Republic era they fell under the dominion of the Rakatan Infinite Empire. As their society declined, Seoul 5 gradually transformed into a myth, its whereabouts unknown and the planet widely believed to have been annihilated in a cosmic war. Nevertheless, Seoul 5 was ultimately rediscovered during the time of the Galactic Civil War. In the time leading up to the open conflict between the Galactic Empire and the Rebel Alliance, an Imperial scout, venturing alone, accidentally located Seoul 5 when his ship veered off course while engaging hyperspace. The scout explored the well-preserved ruins of a sprawling city and came across a substantial deposit of Seoularian crystals. After repairing his vessel, the scout departed, taking a crystal as a souvenir, but the outbreak of war prevented a planned return trip.
This very crystal, along with the coordinates of Seoul 5, ended up in the possession of the Rebel hero Han Solo in 4 ABY, shortly after the Empire's significant defeat at Endor. Upon his arrival on Seoul 5, Solo discovered that he was not the first to find the lost world—an Imperial landing party, commanded by Captain Drezzel, had arrived before him, guided by research conducted by xenoarchaeologists Ualp Xathan and Fem Nu-Ar. A blaster fight erupted between Solo and the Imperials as they both fought over the precious cache of Seoularian crystals; Solo then overloaded the city's crystal control room in an attempt to eliminate the Imperial contingent. Solo, along with Xathan and Nu-Ar, barely escaped the city, leaving the planet deserted once more.
By the time Seoul 5 was rediscovered in 4 ABY, its ancient Human civilization had long since disappeared, but the remnants of their existence remained both on Seoul 5 and its colonial outposts. The inhabitants of Seoul 5, who communicated in a language known as Seoulian, revered the mother goddess Onrai, erecting towering statues of the deity within their urban centers.
Seoul 5 was characterized by the massive cities left behind by the Seoularian civilization; remarkably, some of these cities remained remarkably intact even after the Galactic Civil War, many generations after Seoul 5 was abandoned. At least one city contained a prominent statue of the goddess Onrai in its central square. These cities were powered by unique radiant crystals, stored in chambers and tunnels located deep underground.
Seoul 5 served as the main location in Star Wars (1977) 84, authored by Roy Richardson, illustrated by David Mazzucchelli, and published in 1984.