Sheshnag Lake, Sacred lake in Pahalgam, India

Sheshnag Lake is an alpine oligotrophic lake in the Anantnag district of Jammu and Kashmir, India, at 3,590 metres on the trek to the Amarnath cave, 23 km from Pahalgam. It measures up to 1.1 km long and 0.7 km wide. Its still, opaque pale turquoise-green water meets a low rocky bank of grey stones and sparse groundcover, with a slight inlet on the right.

Sheshnag Lake lies in a groove between snow- and ice-covered mountains; meltwater from those slopes feeds the basin. The lake drains through a stream that joins the Lidder River at Pahalgam. It sits on the pilgrimage track to the Amarnath cave, about 23 km from Pahalgam and 20 km south of the temple.

The lake takes its name from Sheshanaga, the nagaraja or king of all Nagas in Hindu tradition. It lies on the pilgrimage track to the Amarnath cave, about 20 km south of the shrine. An hour's drive from Srinagar, a stone marker commemorates the Kashmiri folk tale "Himal and Nagrai", whose protagonist Nagrai was a serpent king, and with it the Nagas, the original inhabitants of Kashmir.

The lake sits 23 km from Pahalgam; vehicles go 113 km by road to Chandanwari, from where ponies can be hired for the 7 km upslope trek. June to September is the visiting window; from December to March the lake freezes and heavy snowfall makes it inaccessible.

The lake drains through a stream that joins the Lidder River at Pahalgam, so its snowmelt eventually flows past the town where the trek begins. It lies about 20 km south of the Amarnath cave temple and holds brown trout among its fish.