The jyotirlinga enshrined in the temple of Nagnath is known as Nageshwar Mahadev. Temple of Lord Nageshwar is situated in Gujarat. It is on way from Gomti-Dwarka to Bhet-Dwarka. The legend has it that once there lived a demon called Daruka. He lived with his wife Daruki in the city of Darukavanam. Daruka was extremely cruel and used to torture the good ones. Yet he was a great devotee of Lord Siva. One day he captured a ship which was carrying a few people.  All the demons caught hold of the people and put them in prison. Amongst the prisoners there was a prisoner named as Supriya. He was a great devotee of Lord Shiva. He advised all prisoners to recite the mantra ‘OM NAMAHA SHIVAYA’. Daruka began to torture Supriya. Supriya was staunch is his faith in the Lord and was unmoved by any torture. Lord Siva was pleased and appeared and killed the demon Daruka. She-demon Daruki started praying to Goddess Parvati for mercy. The Goddess was pleased with the devotion and blesses her.
In this way Lord Shiva stays and resides there eternally by the name of Nageshwar and Goddess Parvati by the Nageshwari. This powerful jyotirlinga symbolizes protection from all poisons and those who pray to the Nageshwar Linga therefore become poison free.