Located in the Outer Rim, the tiny planet of Mustafar is a fiery world where lava is mined like a precious natural resource. Its bleak landscape is a visual assault of jagged obsidian mountains with towering fountains of fire and lava blasting from beneath the surface. This lava also streaks the blasted landscape in huge winding rivers and plunging cataracts. Mustafar's skies are obscured by choking black clouds of ash, smoke and tephra. The intense geological activity creates natural scanning interference that has kept prying eyes away from Mustafar for most of its history.
These inhospitable features made Mustafar an ideal sanctuary for the ever mobile Separatist Council that led the Confederacy of Independent Systems during the Clone Wars. After repeated setbacks, General Grievous was ordered by Darth Sidious to secure the Council on Mustafar, where they would await further instructions. An enormous cliff-side industrial facility served as headquarters to the commerce baron war chiefs. Neimoidian soldiers and battle droid infantry provided security, while shimmering deflector shields protected the structure from the volatile surroundings.
Upon his ascendancy to Galactic Emperor, Darth Sidious had no further need of the Separatists. He dispatched his new apprentice, Darth Vader, to dispose of his wartime collaborators on Mustafar. Upon arrival, Vader silently stalked into the inner chambers of the mining facility. His lightsaber blade made short work of the Separatists, cutting them down and effectively bringing an end to the Clone Wars.
Amongst this apocalyptic landscape of erupting volcanoes, Jedi Master Obi-Wan Kenobi confronted Darth Vader, his former apprentice. The two entered into a spectacular lightsaber duel that worked its way through the Mustafar collection complex. Through the course of their battle, the protective shields were deactivated, and the facility was exposed to the planet's full geological fury.
A geyser of lava erupted, dropping molten rock on one of the outrigger collection arms of the facility where Obi-Wan and Vader dueled. The arm collapsed under the heat and strain, plunging into the lava river. Before the severed collection arm succumbed to the pull of a lavafall, Vader and Kenobi leapt from the doomed structure onto a nearby worker droid and harvesting platform, respectively. Their duel continued on these cooled repulsorlift surfaces before ending abruptly on the black sand shores of the lava river.
Kenobi bested Vader, leaving the Dark Lord to die on the Mustafar river banks. Darth Sidious sensed Vader's anguish, and arrived in time to rescue his fallen apprentice. Maimed and mortally wounded by lightsaber and fire, Vader was reconstructed as a cyborg and encased in a black protective life supporting suit.
Despite the hellish nature of its environment, Mustafar has nonetheless produced native life capable of surviving in the fiery extremes of the planet. The sentient Mustafarians -- of which two notable subspecies exist -- paid little heed to the galactic events that culminated on their world. They went about their business, gathering precious minerals and energy from the lava streams, riding their massive lava fleas across the stygian lands.