Arunachala refers to the holy hill at Thiruvannamalai in Tamil Nadu, where the Annamalaiyar Temple, a temple of Lord Shiva is located. Every year in the Tamil month of Karthigai (October–November), the Karthigai Deepam (Light) is lit atop the hill. This place is also known by the names Arunagiri, Annamalai Hill, Arunachalam, Arunai, Sonagiri and Sonachalam. It is the most important holy place for people practicing Atma vichara (self enquiry) and one of the 5 main shaivite holy places in South India. The ashram of Sri Ramana Maharishi, Sri Ramana Ashram is also situated at its foothills.

According to the legend, associated with the Temple, a dispute occurred between Brahma the creator, and Vishnu the preserver, over which of them was superior. In order to settle the argument, Lord Shiva is said to have manifested as a column of light, and then the form of Arunachala.

In the Maheswara Khanda of Skanda Purana, sage Veda Vyasa describes in great detail the wonder of Arunachala.

Over the centuries, many saints and sages have been drawn to Arunachala. The Saivite saints Manickavachagar, Appar, Sambandar and Sundarar are four examples. In the fifteenth century, Guhai Namasivaya, Guru Namasivaya and Virupaksha Deva came from Karnataka and settled on Arunachala. Saint Namasivaya lived in one of Arunachala's caves which is still known by his name. Virupaksha Deva lived in an OM-shaped cave higher up on the Hill, and this cave too still bears his name. Located on the south-east slope of Arunachala, this was the cave that Sri Ramana Maharshi lived in from 1899 to 1916.

Sri Ramana Maharshi (Tamil: ரமண மஹரிஷி) (December 30, 1879 – April 14, 1950), born Venkataraman Iyer, was a Hindu spiritual master ("jnani"). He was born to a Tamil-speaking Brahmin family in Tiruchuzhi, Tamil Nadu. After experiencing at age 16 what he later described as liberation (moksha), he left home for Arunachala, a mountain considered sacred by Hindus. He lived at the mountain for the rest of his life. Although born a Brahmin, he declared himself an "Atiasrami", a Sastraic state of non-attachment to anything in life and beyond all caste restrictions. The ashram that grew around him, Sri Ramana Ashram, is situated at the foothill of Arunchala, to the west to the pilgrimage town of Tiruvannamalai.

Sri Ramana Maharshi maintained that the purest form of his teachings was the powerful silence which radiated from his presence and quieted the minds of those attuned to it. He gave verbal teachings only for the benefit of those who could not understand his silence (or, perhaps, could not understand how to attain the silent state). His verbal teachings were said to flow from his direct experience of Atman as the only existing reality. When asked for advice, he recommended self-enquiry as the fastest path to moksha. Though his primary teaching is associated with Non-dualism, Advaita Vedanta, and Jnana yoga, he recommended Bhakti to those he saw were fit for it, and gave his approval to a variety of paths and practices.