The oldest monastery is that of Lamayuru, believed to have been a sacred site for the pre-Buddhist religion known as Bon. The main image is a large Vairocana (the Teaching Buddha) seated on a lion throne with a garuda (mythical bird) and sea monsters surrounding his head. Twice a year, all the lamas gather for prayers, accompanied by three days of masked dancing. These gatherings occur in the second and fifth months of the Tibetan calendar (corresponding usually to March and July). Lamayuru is 125 kms west of Leh at an altitude of 3510 m / 11600 feet.