Ruusan

Originally settled by the Mining Guild as part of a wave of expansion in the Teraab Sector, Ruusan was once a temperate, pleasant world, inhabited by Ruusanians, humans, and a strange sapient species known as Bouncers. It was one of the Old Republic's best sources of lightsaber crystals, and its loss forced the Jedi Order to rely on blue and green crystals from Ilum. During the New Sith Wars between the Jedi Army of Light and the Sith Brotherhood of Darkness under Lord Kaan, a 'thought bomb' was set off and it annihalated everyone on the planet, who's spirits settled in an equilibrium called the 'Valley of the Jedi"