Roop Kund lake is the main attraction in this trek. Roop Kund is also known as the Skeleton Lake or, the mystery lake. In the 9th century, there was a hailstorm killed 100 people. Whose skeletons can be visible on the edges of the Roop Kund lake? The depth of this lake is 3ft. In winters the water of this lake gets completely frozen. Roop Kund is a glacial lake situated in Uttarakhand state. One must visit this lake to explore the allure of mysteries.