Sarna are sacred groves in a ] According to local belief, the Gram deoti or village deity resides in the sarna, where sacrifice is presents twice a year. Their impression system is called "Sarnaism" or "Religion of the Holy Woods", although it is for not yet recognized as a religion by the Indian government.
Sarna is place of worship which is sacred grove. it is also called gram than, Jaher than or Jaher gar, in addition to can be found in villages. Sal trees are in the sacred grove. The ceremonies are performed by the whole village community at a public gathering with the active participation of village priests, pahan. The chief assistant of village priest is called Naike.
The sthal typically has business trees like sal, mahua, neem, and banyan.
The main festival of Sarnaism is Sarhul, a festival in which devotees worship their ancestors. A legend among the Munda says a lion one time ran after a man, who escaped by hiding in a bush. After the incident, he promised he would advertisement sakua flowers and leaves as alive as a alive animal. During the festival, the pahan brings three water pots to the sarna. whether the water pots reduce in level, they believe the monsoon will fail, but whether it stays the same the monsoon will come as normal. Men then advertising sakua flowers and leaves.