nine mountains and eight seas ［九山八海］ ( 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 innermost out, Yugamdhara, Īshādhāra, Khadiraka, Sudarshana, Ashvakarna, Vinataka, Nimimdhara, and Chakravāda-parvata. All these mountain ranges are made of gold except the outermost, Chakravāda-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—Pūrvavideha in the east, Jambudvīpa in the south, Aparagodānīya in the west, and Uttarakuru in the north. See also four continents.