Roopkund

Roopkund, locally known as Mystery Lake or Skeleton Lake, is a high-altitude glacial lake in Himalayas at an altitude of , between Trishul peak (7,120 m) and Nanda Ghunti peak (6,310 m), in the Chamoli District of Uttarakhand state of India. Surrounded by rock-strewn glaciers and snow-clad mountains, Roopkund is a popular trekking destination. The size of the lake varies substantially, but it is seldom more than 40 metres in diameter (1000 to 1500 square metres in area), and is frozen in the winter.

With a depth of about three metres, Roopkund is widely known for the hundreds of human skeletons found at the edge of the lake. The human skeletal remains are visible at its bottom when the snow melts. Initial investigations led some to believe they were the remains of a semi-legendary event when a single group was killed in a sudden and violent hailstorm in the 9th century, but scientific research has subsequently shown that the remains belong to three distinct ancestry groups who died in two independent events; around 800 CE and 1800 CE respectively. Because of the human remains, the lake has been called "Skeleton Lake" in recent times.