Glory of Arunachal Shiva Linga from Skanda Purana

Once, Sutji had gone to Naimisharanya. All the sages residing there asked him about the manifestation of Arunachal Shivalinga. Sutji recounted a tale when Sage Sanak had posed the same query to Lord Brahma – 'Lord Brahma had told Sanak-Son, once Lord Vishnu and I witnessed an effulgent Pillar. It had manifested from nowhere and was limitless in size. It's radiance put the whole world ablaze. Both of us worshiped that marvelous pillar by chanting vedic mantras.' Actually, that effulgent pillar was a Shivalinga. Lord Shiva manifested from it after being pleased by our devotion. We requested him to minimize his size and establish himself in the form of Arunachal Shivalinga.'

'Lord Shiva agreed to minimize his size as well as his effulgence by establishing himself in the form of 'Arunachaleshwar'.The holy place of Arunachaleshwar remains untouched while the whole world gets submerged in water at the time of deluge.