Mos Osnoe was a relatively small urban center and facility for interstellar travel, both situated on Tatooine, a desolate world. You can read more about cities and spaceports or deserts and planets on Tatooine.
This location once housed a spaceport operated by the Galactic Republic during the period known as the Clone Wars. Sev'rance Tann, a commander serving the Separatist forces, traveled to this city to rendezvous with Boorka, a member of the Hutt species, at a time when Boorka was plotting to double cross the Republic's military presence in the area.
Subsequently, Echuu Shen-Jon, a Jedi General, along with his soldiers, interfered with the alliance between Boorka and the Separatists, ultimately forcing the Separatist forces to retreat from the Mos Osnoe area. While present in the city, Shen-Jon also provided assistance to local officials and inhabitants of the neighboring Jundland Station, aiding them in the destruction of a Tusken Raider encampment shortly following Tusken attacks on Mos Osnoe.