The Greater Celestial River is the larger of the two Celestial Rivers in the sky, with the lesser one located around Diadem. The river is quite vast, being as wide as a lake in some parts. The entire route of the river isn't known, but the area seen is far west in the Sky and the source is sometimes speculated to be the ice lands of Wazn. Across the river, various floating chunks of rock can be seen; this phenomena has had implications in certain debates about the World of the Baten Kaitos series. The area is inhabited by various monsters and the river itself by the Thunderfish.