Atrishwara

Atrishwara Linga in a forest named Kamda on Chitrakuta Mountain where the Maharshi saved people from prolonged drought for some fifty years; once Arti fainted out of thirst and his wife Anasuya went in search of water; Devi Ganga appeared and offered water from a spring and Anasuya carried a Kamandalu-full of water and quenched Atri’s thirst. It was from that Spring emerged the Sacred Mandakini River and as the result of the Tapasya, the prolonged drought ended and Bhagavan Shiva appeared as the Atrishwara Linga.

https://shivamahapurana.wordpress.com/2012/02/26/atrishwara-incarnation-greatness-description/