The Celadon Sea was a poisonous mist that covered the icy mountain ranges on the planet Carnelion IV. Grecker, a member of the Closed, blamed the Open for destroying their world and creating the Celadon Sea. In 29 BBY, Jedi Knight Obi-Wan Kenobi and his Padawan, Anakin Skywalker, crash-landed in the Celadon Sea while investigating a distress signal. Located beneath it was "The World That Was," the remains of an advanced civilization destroyed in a war between the Open and the Closed. Except for individuals with breath masks, the Celadon Sea transformed the planet's human population into beasts known as Fishers, who lived in the city's ruins, forcing the survivors to take refuge above the Sea in the freezing mountains.