Saptarishi Kund — the 4422m alpine lake of the seven sages.
Char Dham yatris reach the Yamunotri temple at 3293m and turn back — almost none continue 10km higher to the seven alpine lakelets where the Saptarishi (seven sages) are said to have done penance per the Skanda Purana, despite this being the actual glacial-watershed origin region of the Yamuna.WHY NOBODY KNOWS
Saptarishi Kund sits at 4422m above Yamunotri temple, accessed via a strenuous unmarked trail past Champasar Glacier (the Yamuna's real glacial source). The kund is a cluster of seven small alpine lakelets fed by Bandarpoonch ice melt — per the Skanda Purana these are where the Saptarishi (Vasishtha, Vishvamitra, Kashyapa, Atri, Jamadagni, Bharadwaja, Gautama) did tapasya before the Yamuna manifested. Permits via Uttarkashi DFO mandatory; the trail is open only August-September (snow-free window). High-altitude porters from Janki Chatti can be arranged at the trailhead but you need to be fit and pre-acclimatised — most fail this trek. The lakelets remain frozen or partially frozen even in monsoon-end.
