Lake Teletskoye lies in the north-east of the Altai Republic, in the Turochaksky and Ulagansky districts. It covers 223 km² and is up to 323–325 m deep, which makes it the fifth deepest lake in Russia; it holds about 41 km³ of water.
Teletskoye is often called Baikal's younger brother, and the two do have something in common. About 70 rivers and some 150 seasonal streams flow into the lake, and only one river, the Biya, flows out, just as the Angara is the only river flowing out of Baikal. About 98 % of the water leaves through the Biya and the rest evaporates; the Chulyshman brings 70 % of the inflow, and its delta is at the southern end of the lake. But Teletskoye is not Russia's second largest store of fresh water after Baikal: Lake Ladoga holds 20 to 23 times as much water, Lake Onega about seven times as much. Nor is the nickname unique: Lake Khövsgöl in Mongolia goes by it too.
Reference books give the water's transparency as 6–14 m; in summer 2018 a Secchi disk stayed visible at depths of 1 to 11.7 m. Between 2014 and 2023 the average August transparency fell from 8.2 to 5.3 m as the lake gradually becomes more eutrophic. For comparison, on Baikal a Secchi disk can be seen down to 40 m.
The lake basin is young by geological standards: it formed in two stages, from the early Quaternary to the Holocene, in less than a million years. Baikal is 25–35 million years old.
The northern part of the lake, which runs east to west, freezes every winter in November and breaks up in late April or early May. The deep southern part freezes only in January, and in some years, on average once in three, does not freeze at all. The ice is clear: near the shore the bottom can be seen through it at a depth of 5–6 m.
Asphalt reaches only the northern end of the lake, the villages of Artybash and Iogach, which are linked by a bridge. The southern end can be reached by water or over the Katu-Yaryk pass. On the eastern shore, 26 km from the source of the Biya, lies the village of Yaylyu with the headquarters of the Altai Nature Reserve. Scheduled buses run daily to Artybash from Gorno-Altaysk, which has an airport. Distances are quoted differently: OpenStreetMap roads give about 160 km and under three hours' driving, while the republic's tourism portal speaks of 250 km and four hours.
The Korbu waterfall, 12.5 m high, is inside the Altai Nature Reserve and can be reached only by water, 25 km by boat from Artybash. A 200-metre path leads from the landing, and the walk takes 30–40 minutes. The waterfall is open from May to September, and the reserve's entry ticket serves as the permit.
Do not expect solitude: this is one of the most visited places in the Altai Republic, with 18 holiday camps and campsites on its shores. Navigation opens in late April or May, and July and August are best for boat trips and hiking. Since 7 September 2026 catching taimen has been banned in all waters of the republic, and grayling are limited to 10 per day.
