Koteshwar Mahadev, who is said to be a sacrificed soul sanctified by Lord Shiva himself, is regarded as the King of Kumarsain, a small village around 75 kilometres north of Shimla, the capital of Himachal Pradesh.

Koteshwar Mahadev is a popular god in Kumarsain and the surrounding area. The holy temple of the deity is located near Kumarsain's village, Mandoli. He is one of Lord Shiva's avatars. Mahadev emerges from the temple just once every four years.

In the months of August and September, a large fair is conducted here. The deity is adorned with garlands of fragrant flowers and coins, numerous decorations, and a golden crown as well as a gold umbrella; other Koteshwar Mahadev idols are lined up beneath this primary idol.

Devta's face exudes calm, happiness, and endless satisfaction .It appears that the individuals carrying the palanquin plan themselves, whereas it is stated that Devta controls the palanquin, thousands of devotees gather to worship him.

Kumarsain Jatar lasts for 9 days, with 5 days spent in Kumarsain and 4 days spent in Mandoli. On the first day, Koteshwar Mahadev and Marich Devta are carried out of Sharkot and taken to their respective temples; Koteshwar Mahadev to Mandoli and Marich to Bai Temple.

Koteshwar Devta and Buda Devta travel to Shrambal Camp in the evening since it is the main location from which the Koteshwar Devta can be seen.

The following day, Koteshwar Mahadev and Budda Devta  meet with Marich Devta. Malandi Devta attends the expo on the third day.

All the deities go to Madholi on the sixth day. Marich and Malendi Devta bid Koteshwar Devta farewell in the last two days.

Those leaving Devtaa are unwilling to go because their palanquins will not let their bearers use the departure route, despite the fact that Koteshwar Mahadev waits at the end of the road to see them off. Only the interruption of the most senior 'Gur' (priest) persuades them to stay for another four years.

The festival concludes with a 'Nati' (local dance) performed by Kumarsain residents.

The Fair of Custom, Belief, and Divinity.

Jai kaar Koteshwar Mahadev