During the days of Saivite Saints Appar, Gnanasambandar and Sundarar, the place was known as Pazhamalai in Tamil and changed to the Sanskrit version Vruddhachalam in the days that followed. Vruddham means ancient and Achalam hill. It is also said that Lord Shiva appeared here only in the form of this mount and other mounts came into being only later, according to scriptures. Sage Vibasithu had a dip in the Manimutha river and undertook the renovation of his temple. He gave the workers the leaves of the Vanni tree which later changed into coins to the value due to the workers based on the quantum and quality of his work, is a story believed by generations of devotees. The Vanni tree is 1700 year old, say researchers.