Shaligram or Ammonite fossil is a darkish stone characterized by the presence of discus marks on it. It is the most sacred stone worshipped by the Vaishnavas. It is found on the bank of River Gandaki (which is a Himalayan stream, celebrated since history as Narayani, Saligrami and Hiranyavati) in Nepal. There is a lake at the source of the Kali Gandaki, called Damodar Kunda, (a place of pilgrimage) at Nepal. The lower Gandaki is well known as Mukti Natha Kshetra or Shaligrama Kshetra. The sacred stones are largely found on the banks of Kali Gandaki.
Historically, the use and worship of Shaligram can be traced to the time of Adi Shankara and finds mention in his works. His commentary suggests that the use of Shaligram in the worship of Vishnu has been a well-known Hindu practice.