Static or immobile. It has been said that, at the time of pralaya (doomsday), the mountains of the previous epoch melted in the fire, caused by pralaya, called saṃvartaka (samvartaka). Wherever these molten mountains fell, having been blown by strong gusts of wind, they became static after solidifying upon crystallisation after coming in contact with the cool water of the turbulent seas of pralaya. Since they became acala (achala), that is, static, they are referred to as acala. There are various joints or knots (parvasandhi) between the acala; as a result, acala are also known as parvata (mountains).