Kausar Nag or Kausarnag (sometimes alternatively spelled as Konsarnag), is a high-altitude oligotrophic lake located at an elevation of 3,500 metres (11,500 ft) above sea level.

[1] Kausar Nag is located in the Pir Panjal mountain range in Kulgam district of Jammu and Kashmir, India.

According to the Nilamata Purana, after the great flood, the boat of Manu that carried the Vedas and the Saptarishi was stuck in the mountains above the lake.

[4] Sultan Zain ul Abedin is said to have visited the lake, as a symbolic gesture to persuade the exiled Hindus of Kashmir to return.

[4] There are two routes traditionally used for Hindu pilgrimages (called yatra) to the lake, one through Kulgam in the Kashmir Valley and the other via Reasi in the Jammu region.