Omkareshwar, the sacred island, shaped like the holiest of all Hindu symbols, 'Om', has drawn to it hundreds of generations of pilgrims. Here, at the confluence of the rivers Narmada and Kaveri, the devout gather to kneel before the Jyotirlinga (one of the twelve throughout India) at the temple of Shri Omkar Mandhata. And here, as in so many of Madhya Pradesh's sacred shrines, the works of Nature complement those of man to provide a setting awe-inspiring in its magnificence. Narmada forms a deep silent pool which in former times was full of alligators and fish, so tame as to take grain from human hand. This pool is 270 ft below the cantilever type bridge constructed in 1979. The bridge has enhanced the scenic beauty of the place, making it look exceedingly picturesque.
Omkareshwar is a Hindu temple in the Khandwa district of Madhya Pradesh state in India. It is on an island called Mandhata or Shivapuri in the Narmada River. It is one of the 12 revered Jyotirlinga shrines of Shiva. It is about 12 miles (20 km) from Mortakka in Madhya Pradesh. The shape of the island is said to be like the Hindu Om symbol. There are two temples here, one to Omkareshwar (whose name means "Lord of Omkaara or the Lord of the Om Sound") and one to Amareshwar (whose name means "Immortal lord" or "lord of the Immortals or Devas").
Omkareshwar is formed by the sacred river Narmada. This is one of the most sacred of rivers in India and is now home to one of the world's biggest dam projects.
The story of Omkareshwar Omkareshwar Jyotirlinga also has its own quota of stories.Three are prominent. The first story is about Vindhya Parvat (Mount). Once upon a time Narada (son of Lord Brahma), known for his non-stop comic travel, visited Vindhya parvat. In his spicy way Narad told Vindhya Parvat about the greatness of Mount Meru. This made Vindhya jealous of Meru and he decided to be bigger than Meru. Vindhya started worship of Lord Shiva to become greater than Meru. Vindhya Parvat practiced severe penance and worshipped parthivlinga (A linga made from physical material) along with Lord Omkareshwar for nearly six months. As a result Lord Shiva was pleased and blessed him with his desired boon. On a request of all the gods and the sages Lord Shiva made two parts of the lingas. One half is called Omkareshwara and the other Mamaleshwar or Amareshwar. Lord Shiva gave the boon of growing, but took a promise that Vindhya will never be a problem to Shiva's devotees. Vindhya began to grow, but did not keep his promise. It even obstructed the sun and the moon. All deities approached sage Agastya for help. Agastya along with his wife came to Vindhya, and convinced him that he would not grow until the sage and his wife returned. They never returned and Vindhya is there as it was when they left. The sage and his wife stayed in Srisailam which is regarded as Dakshina Kashi and one of the Dwadash Jyotirlinga.
The second story relates to Mandhata and his son's penance. King Mandhata of Ishvaku clan (an ancestor of Lord Ram) worshipped Lord Shiva here till the Lord manifested himself as a Jyotirlinga. Some scholars also narrate the story about Mandhata's sons-Ambarish and Mucchkund, who had practiced severe penance and austerities here and pleased Lord Shiva. Because of this the mountain is named Mandhata.
The third story from Hindu scriptures says that once upon a time there was a great war between Devas and Danavas(demon), in which Danavas won. This was a major setback for Devas and hence Devas prayed to Lord Shiva. Pleased with their prayer, Lord Shiva emerged in the form of Omkareshwar Jyotirlinga and defeated Danavas.