Teletskoye Lake, known as 'Baikal's little brother', is the largest lake in the Altai Mountains and the second deepest freshwater lake in Siberia. Surrounded by mountains covered with pristine taiga, it stretches for 78 km and remains cold even in summer. The lake is part of UNESCO World Heritage site 'Golden Mountains of Altai' and home to rare fish and wildlife species. Boat excursions to waterfalls and secluded bays are the primary way to explore it.