Situated at 3680m, Tungnath is highest Shiva temple in the world. Stated to more than 100 years old, the legend has it that after the great war, Pandavas searched for Shiva to obtain his blessing, to free them of the guilt of killing their relatives, but the god remained elusive.
He changed into a bull and at Kedarnath dived under the ground, leaving his hump behind. Other parts of him, appeared nearby, his arms at Tungnath and naval at Madhmahesvara, his face at Rudranath, his head, and hair at Kalpeshvara. Together with Kedarnath, they form Panh Kedar. The present temple was built by Pandavas to appears Lord Shiva.
Wondering how to reach Tungnath and also a get glimpse of Chandrasheela Peak, read this write up from Shaily from RougePouts, you could trek to reach the base camp which is Chopta or simply drive to Chopta.