According to the Hindu mythology Sheshnag means the king of snakes and the lake was dug by Sheshnag himself. It is believed by the Hindus that Sheshnag stays in this Lake even today. It is one of the most ancient places of pilgrimage for the Hindus, as it lies on the track of Amarnath cave.
Sheshnag Lake is home to many types of fishes among of which is the brown trout. It freezes during winter, and is inaccessible during this season due to heavy snowfall. It is surrounded by green lush meadows and mountains covered by snow. Sheshnag Lake is one of the famous tourist destination in Kashmir Valley. It is mostly fed by melting of snow and streams coming down from mountain tops. It drains out through a stream which joins Lidder River at Pahalgam.
Sheshnag Lake is situated 120 kilometers east from Srinagar and 23 km from Pahalgam. It can be accessed 113 km by road up to Chandanwari from which ponies can be hired to cover a trek of 7 km upslope to reach the Sheshnag Lake. Amarnath cave is situated 20 kilometers north of this lake. The best time to visit the lake is from the month of June to September.
(source:jktourism.org). The address of Sheshnag Lake, Pahalgam is Pahalgam
It's in Pahalgam