The most fundamental of Hindu deities, is the Trinity of Brahma, Vishnu and Shiva - popular deities include Ganesha, Krishna, Hanuman and goddesses like Lakshmi, Durga,Saraswati.
Shiva's spirit, his radiance, jyoti, is said to be locked in twelve different lingas located in different parts of India. These are some of the holiest Shaivite shrines.
Once Ravan cut off nine of his ten heads to propitiate Shiva. Shiva was so pleased that he gave Ravan a jyotir-linga containing his radiant spirit. The gods feared that with the sacred linga by his side Ravan would become invincible and threaten cosmic well-being. On his way to Lanka, Ravan experienced the terrible urge to answer the call of nature. He asked a local cowherd to hold the sacred linga while he relieved himself. But the cowherd could not hold on to it for long. He placed the linga on the ground. There it remains till this day.
The linga came to be known as Vaidyanath, the great physician, because Dhanvantari, the divine doctor and founder of Ayurveda is said to have merged with this linga. This shrine is also associated with Markandeya, the devotee whom Shiva saved from certain death.
Some believe, that the linga containing Shiva's soul, atma, was established by Ravan at Gokarna, on the Kanara coast. Ravan tried to uproot the linga, mutilating it, until it looked like a cow's ear gokarna. Hence it is called the Gokarna-linga of the strong-god, Mahabaleshvar.
It is interesting to note that both Ram and Ravan, who were sworn enemies, worshipped Shiva and established Shiva temples.
Vishvanath At Benaras-Kashi along the river Ganga in the Kashi Vishwanath Temple
Shaileshvar Along the river Patalganga in Andhra Pradesh at the Shaileshvar Mallikarjun temple.
Mahakaleshvar Along the river Kshipra in Ujjain is the Mahaklaeshwar temple where he is present as the Mahakaal
Bhimeshvar or Bhimashankar At the banks of the river Bhima in the Sahyadri Mountains in Maharashtra
Kedarnath In Himalayas
Omkareshvar On an island of river Narmada in the Vindhyanchal Mountains of Malwa in Rajasthan
Somnatheshvar On the shores of Saurashtra, Gujarat, stands Somnatheshvar. This is the holy land of Prabhasakshetra, the land of radiance, where lord Krishna is said to have died.
Trimbakeshvar Along the river Godavari in Maharashtra
Nageshvar At Aundh in Maharashtra
Rameshvar This shrine is located near the southern tip of India in Tamil Nadu.
Ghushmeshvar This shrine is near Aurangabad. This shrine is also called Ghrishneshvar.
Vaidyanath This shrine is located in Marathwada, though some believe it is at Purulia, West Bengal. It was established by Ravan, the king of the rakshasas, quite accidentally