The u-curve in center is the area Of Roop Kund.
While Trekking to roop kund one crosses the place Patal-nachna.
This is the place where demons from hell, have danced in the marriage of Lord Shiva.
and it is believed that anyone not going to Roop Kund with faith or good intentions. these demons doesnt allow the trekkers to pass this area. Something or other will happen to them.
Another interesting fact about Roop Kund is till date no one clear about the skeletons at the place.
some say that long ago a king with army got stuck their and got buried under the snow.
some say that were the local people who got trapped in the snow strom during the yatra(holy voyage) called Raj-jat. under this the people starting from a place around AAdi badri in Chamba area and from other place gets collected at one palce and goes till the homkund with a Holy goat having four horn.
The Goat i just talked about, above. It is said that in tweleve year this goat born only once and automatically reached to the family on which the responsibility of conducting the Raj-jat is their.
the speciallity of this goat is that it has four horn in which the sculpture of mata Parvati can be placed. it is same as some one sit on a chair.
This goat after reaching Hom-kund is left alone and from theron this goat cover the rest of the way on its own.