"Silu" (Devanagari: सिलु) is a traditional Nepalese song about a couple from Kathmandu who go on a pilgrimage to Silu and get separated. The ballad in Nepal Bhasa dates from the early 19th century. 
Silu is what the Newars call Gosaikunda, a holy lake located to the north of Kathmandu.  Situated at an elevation of 4,380 m in the Himalaya, it is associated with the Hindu deity Lord Shiva. The lake is also held sacred by Buddhists who associate it with the Bodhisattva Avalokitesvara.
The epic song is in the form of a dialogue between the husband and wife. When he announces his plan to visit Silu to take part in the ritual bathing festival, she expresses her desire to go with him. He tries to dissuade her by reminding her of the saying that a husband and wife going together is bad luck. But she insists, and he lets her come along.
When they reach Silu, the king sees her and sends soldiers to take her away and forcibly makes her his queen. The depressed husband leaves home and becomes an ascetic.
One day, the queen asks the king to assemble all the ascetics on the palace grounds to give them alms. The sadhus are gathered as per her wish, and when she spots her husband among them, she slips away with him disguised as a nun. The couple are thus reunited.
Silu Wanegu, the pilgrimage to Silu to take a holy dip in the lake, is a long-standing tradition in Newar society. The trek is done in August, when a festival is held on the full moon day.
The first few lines of the song appear below.
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