On Janai Purnima, a full moon day, high-caste Hindus chant the powerful Gayatri mantra and change their Sacred Thread (janai), while a raksha bandhan, a red or yellow protection cord, is tied around the wrists of other Hindus and Buddhists. Pilgrims journey to the mountains north of Kathmandu. Here they emulate Lord Shiva by bathing. in the sacred lake of Gosaikund. Those unable lo make the trek celebrate at Shiva's Kumbheswar Mahadev temple. Here, a pool with an image of Shiva at its center is filled with water believed to have come from Gosaikund.