The ancient name of Mount Abu is Arbudaanchal. In the Puranas, the region has been referred to as Arbudaranya ("forest of Arbhuda") and 'Abu' is a diminutive of this ancient name. It is believed that sage Vashistha retired to the southern spur at Mount Abu following his differences with sage Vishvamitra. There is another mythology according to which a serpent named "Arbuda" saved the life of Nandi (Lord Shiva's bull). The incident happened on the mountain that is currently known as Mount Abu and so the mountain is named "Arbudaranya" after that incident which gradually became Abu.