Serenno City was a city located in a valley near Castle Serenno, the headquarters of House Serenno, during the reign of Dooku, a former Jedi turned Sith Lord, as Count of Serenno, below the cliff that the palace was situated upon and opposite the eastern ridge on the Outer Rim planet Serenno. The city was close to the upper forest region of the planet and beyond a forest. After the end of the Clone Wars, the city was destroyed by the Galactic Empire via an orbital bombardment. In 19 BBY, Hunter and Wrecker who were members of Clone Force 99 attempted to use the city ruins to evade Wilco's company led by Clone Captain Wilco.
When the Clone Wars erupted between the Galactic Republic and Confederacy of Independent Systems, Dooku funded his war effort by not only exploiting other worlds but also stealing from his own people which included the inhabitants of the city. After Dooku's death, shortly before the end of the Clone Wars, the Galactic Empire formed out of the Republic conquered and occupied Serenno. The city was destroyed by orbital bombardment, leading to surviving Serennians such as Romar Adell to take up life in hiding in places like Serenno's upper forest region.
Wrecker and Hunter in the ruins of the city
Some time after the city's destruction, the members of the renegade clone commando unit Clone Force 99 attempted to steal some of Dooku's war chest while Imperial forces were preparing to ship it offworld. When things started to go wrong, the squad was split up and the team's leader, Hunter, and his teammate Wrecker escaped into the ruins of the city while attempting to avoid Clone Captain Wilco and his company of clone troopers.
Wilco led a pursuit into the city and gained a visual on the two renegade clones while attempting to surround them. Wrecker, however, improvised a cannon out of a destroyed Separatist tank which he used to blast a path through the Imperial forces. Hunter and Wrecker escaped the ruins of the city and returned to their starship, the Marauder, to pick up the other members of the team before departing the planet.
The lighting concept of Serenno City was done by Molly Denmark.
The city first appeared in the Star Wars: The Clone Wars third-season episode "Nightsisters," although it was first explored as a location in the Star Wars: The Bad Batch second-season episodes "Spoils of War" and "Ruins of War." The exterior of the city lighting concept was done by Molly Denmark who also did the lighting concept of an Alpha-3 Nimbus-class V-wing starfighter flying over the city.