Dxun is the moon of Onderon, a fictional planet in the Star Wars universe that appears in the video game Knights of the Old Republic II: The Sith Lords, among other sources.
It is told throughout the Star Wars universe that the Mandalorian Wars began on the moon of Dxun, where the former leader of the Mandalorians, Mandalore the Indomitable, had been killed at the end of the Great Sith War. Before the Great Sith War, Freedon Nadd's spirit guided the young Padawan Exar Kun to his tomb, where his mummy and Queen Amonoa and King Omnin rested. He told Kun to take the scrolls that would lead him to Korriban.
During the time of Knights of the Old Republic II: The Sith Lords, Canderous Ordo, taking the title of Mandalore gathered the remaining Mandalorians, most of which were mercenaries at the time, on the moon of Dxun. There they regrouped, later helping the Jedi Exile destroy the battle cruiser known as the Ravager, which had been resurrected from the long since destroyed world of Malachor V,(were the last battle of the mandalorian wars took place) by the Sith Lord Darth Nihilus.
Dxun houses the tomb of Dark Lord of the Sith Freedon Nadd, who had conquered and ruled Onderon before his death, and many other Onderonian leaders.
Read more about this topic: List Of Star Wars Moons