Lake Sapsho is situated in the north-west of Smolensk Oblast, 120 km (75 mi) to the north of Smolensk.
It is on the Sloboda Upland (Russian: Слободская возвышенность) that is a part of Smolensk–Moscow Upland (Russian: Смоленско-Московская возвышенность).
It is the largest lake in Smolenskoye Poozerye National Park.
There are two eskers.
One of them is partly destroyed by glacial flows.
It caused the arising of five of six islands.
Lake Sapsho is divided into deep northern and shallow southern parts.
The other esker forms the western border of the lake.
The northern side is also abrupt.
On the contrary, the eastern and southern sides are gentle.
The bottom of the lake here is also not steep.
The northern basin is divided into western and eastern parts by a long underwater spit.
The depth here is less than 5 m (16 ft).
It ends with a long shoal with depth less than 1 m (3 ft 3 in), a so-called "underwater island" or "sitnik".

Lake Sapsho drains into the rivers of the Western Dvina (Russian: Западная Двина) basin.
In spring, usually by the middle or end of April, water volume increases because of melting snow.
The melting of ice on the lake usually takes from 10 to 15 days more, and ends in the late April or early May. The swimming season opens in late June or early July, and finishes in late July or early August.
The lake usually covers with ice in the 2nd or 3rd decade of November.
Sometimes, it happens in the middle of December.
The thickness of ice is from 50 cm (20 in) to 70 cm (28 in).
In most severe winters it may become up to 90 cm (35 in).
The period of freeze-up is from 150 to 170 days.
Lake Sapsho is situated in the north-west of Smolensk Oblast, 120 km (75 mi) to the north of Smolensk. It is on the Sloboda Upland (Russian: Слободская возвышенность) that is a part of Smolensk–Moscow Upland (Russian: Смоленско-Московская возвышенность). It is the largest lake in Smolenskoye Poozerye National Park. There are two eskers. One of them is partly destroyed by glacial flows. It caused the arising of five of six islands. Lake Sapsho is divided into deep northern and shallow southern parts. The other esker forms the western border of the lake. The northern side is also abrupt. On the contrary, the eastern and southern sides are gentle. The bottom of the lake here is also not steep. The northern basin is divided into western and eastern parts by a long underwater spit. The depth here is less than 5 m (16 ft). It ends with a long shoal with depth less than 1 m (3 ft 3 in), a so-called "underwater island" or "sitnik".
Lake Sapsho drains into the rivers of the Western Dvina (Russian: Западная Двина) basin. In spring, usually by the middle or end of April, water volume increases because of melting snow. The melting of ice on the lake usually takes from 10 to 15 days more, and ends in the late April or early May. The swimming season opens in late June or early July, and finishes in late July or early August. The lake usually covers with ice in the 2nd or 3rd decade of November. Sometimes, it happens in the middle of December. The thickness of ice is from 50 cm (20 in) to 70 cm (28 in). In most severe winters it may become up to 90 cm (35 in). The period of freeze-up is from 150 to 170 days.
Lake Sapsho