Roopkund is a pristine high altitude lake at 4800m. Situated at the base of the massive Trishul Peak (7120m) this lake has an interesting history and tradition associated with it. Roopkund is located on a popular pilgrimage route and is part of a popular fest held every 12 years called the "Nanda Devi Jat Yatra". Several hundreds of skeletons are found here, believed to be from a pilgrimage party (consisting of nearly hundred people) which perished here several centuries ago in a single calamity, possibly a hailstorm. This skeletons are seen floating in the lake and surroundings when the snow melts.
A very popular trek the Roopkund trek offers splendid views of the Himalayas. Along with the thrill of high altitude, views of massive peaks like Nanda Ghunti and Trishul one can experience the delights of walking on Asia's largest and highest meadows-the Ali Bugyal and Bedni Bugyal.
I did this trek with the "Indiahikes" group. The facilities and expertise provided by them were excellent. Specially commendable was the fact that they kept our safety as priority and took special efforts to keep us comfortable not only during the trek but also when we were stuck at the base camp after completion of the trek due to the continuous rains in Uttarakhand which created havoc recently. You can view their website here.