When you go for the Roopkund trek, a lot of mystery and natural charm is in store for you. The Roopkund alpine lake is situated roughly at 16499 feet above sea level. It is also called Skeleton Lake due to the human skeletons, which have been discovered in and around it. There have been various theories on who these skeletons are of and when did they die. Some say that they belong to Japanese soldiers who died here during WWII. Studies have determined that they are of people from an Indian tribe, who died here in the 9th century because of a severe hailstorm.