The cold glacial river that runs past the Kedarnath temple, fed by the Chorabari and Companion glaciers and flowing down to join the Alaknanda at Rudraprayag. The Mandakini is considered holy and many pilgrims take a ritual bath in the icy water near the temple before entering for darshan.
The river is also the reason for Kedarnath's destruction in 2013: a glacier-lake outburst flood roared down this valley and tore apart everything below. The new flood-defence walls on either side of the river are a sobering feature of the rebuilt town.