The lake is an important pilgrimage destination in the state, especially among the Gaddi tribes. It is believed that Lord Shiva created Manimahesh after his marriage with Goddess Parvati, who is worshipped as Mata Gojra. There are plenty of legends about encounters with Lord Shiva and the display of His displeasure through avalanches and blizzards.
On the margin of the lake is a small marble Shivaling called Chaumukha.
The yatra is held every year during the month of August or September. Thousands of people visit the lake to bathe in its sacred water, on Radha asthami , the 15 th day following the festival of Janmashtami every year. It is a colourful procession that starts from the Laxmi-Narayan temple in Chamba town and goes right upto the lake. It takes about 6 days to reach the lake. Pilgrims carry a sacred ‘Chhari' on their shoulders. On reaching the lake, a night long ceremony is held and on the next day the devotees take a holy dip in the lake.After bathing in the holy waters, the pilgrims go around the lake three times.
(Source: http://www.indiatravelite.com )