Arunachala (IAST: ], red mountain), is a hill in Tiruvannamalai, Tamil Nadu and one of the five main shaivite holy places in South India. The Annamalaiyar Temple, a temple of Lord Shiva is located at the base of the hill. The hill is also known by the names Annamalai, Arunagiri, Arunachalam, Arunai, Sonagiri, and Sonachalam.