nine mountains and eight seas
九山八海 (Jpn kusen-hakkai )
The mountains and seas that constitute the world, according to ancient Indian cosmology. The nine mountains are Mount Sumeru at the center of the world and eight concentric mountain ranges that surround it. Eight concentric seas separate these mountain ranges. According to The Dharma Analysis Treasury, the eight circular mountain ranges are, from the inner-most out,
All these mountain ranges are made of gold except the outermost, Chakravada-parvata, also known as the Iron Encircling Mountains, which is made of iron. Mount Sumeru and the eight mountain ranges are each separated from one another by a sea. The distance between Mount Sumeru and Mount Yugamdhara is eighty thousand yojanas. The inner seven seas are of fresh water, while the outermost sea, just inside the iron mountain range, is salty. In this sea are four continents—Purvavideha in the east, Jambudvipa in the south, Aparagodaniya in the west, and Uttarakuru in the north.
See also[ four continents.