The Kessel prison, also the Imperial Correctional Facility, was a prison created to keep various people who were dangerous to the Galactic Empire locked away. Later, there was a revolt, and a prison employee named Moruth Doole, a Rybet, took it over and forced former Imperial guards to work in the spice mines of Kessel. He employed the former prisoners as his own personal guards.
Rebel Alliance pilot Wedge Antilles was shot down and captured during the assault on Kile II. He traveled by armored hovertrain to the prison, but was released by Rogue Squadron before arriving there.
Han Solo and Chewbacca were on a diplomatic trip to Kessel when they were captured by Doole and forced to work in the spice mine. They escaped with the help of Kyp Durron.