Narmadeshwar is a stand alone temple which is open from 06.00 a.m. to 9.30 a.m. and from 6.00 p.m. to 7.00 p.m. Aarti is held in the evening.
It t was revealed that long time back, river Narmada offered intense prayers to Lord Brahma and the latter appeared before her. Narmada asked Lord Brahma that she should be treated equivalent to river Ganga. On hearing this, Lord Brahma was taken aback and he stated that there is no God equal to Lord Shiva, no Purush equal to Maha Vishnu and no river equal to Ganga.
Narmada was not pleased with the response. She came to Kashi, installed a Ling near Trilochaneshwar near Pilpila Teerth and started invoking Lord Shiva, who appeared before her and granted her a divine wish. Narmada only craved for the divine bhakti and darshan of the Lord. Lord Shiva granted that all stones in the river bed of Narmada will be treated as Shiv Ling. He granted her one more divine wish. A devotee who takes bath in Ganga is cleansed of his sins.
A devotee who takes bath in Yamuna for one week is cleansed of his sin and one who takes bath for three days in Saraswati becomes pure. However, if a devotee simply sees the river Narmada he will be cleansed of his sins. Lord Shiva also granted that the Ling established by Narmada would be called as Narmadeshwar. This Ling will be capable of granting Mukti to its devotees. Merely by looking at this Ling, a devotee will be cleansed of all his sins. After saying this, Lord Shiva disappeared into this Ling. (Kashi Khand, Chapter 92).
Lord Skanda who was narrating this to Sage Agasthya said that a girl who even listens to the Mahatmya or reads this chapter relating to Narmada will be cleansed of her sins.