Rakshas tal
Lake Rakshastal is a lake in Tibet, lying just west of Lake Manasarovar and south of Mount Kailash.
[1] The Sutlej River originates at Rakshastal's northwestern tip. Despite its close proximity to Lake Manasarovar (about 3.7 kilometres or 2.3 miles), Lake Rakshastal does not share the historic religious significance of its eastern neighbor.

The name of the lake literally means "lake of the demon" in Sanskrit. It is also known as Ravana Tal, as it is considered to be the place of severe penance by Ravana, the demon-like egoistic King of Lanka in Hindu theology .

[2] In Buddhism, Lake Manasarovar, which is round like the sun, and Rakshastal, shaped as a crescent, are respectively regarded as "brightness" and "darkness". Its salty water, in stark contrast to the fresh water of Lake Manasarovar, results in there being no aquatic plants or fish, and is considered poisonous by locals.
There are four islands in Rakshastal, named Topserma (Dose), Dola (the two biggest), Lachato (Nadzhado), and Dosharba.[3] The islands are used by local people as winter pastures for their yaks.