Bogdinsko-Baskunchakski Nature Reserve (Russian: Богдинско-Баскунчакский) (also Bogdinsko-Baskunchaksky) is a Russian 'zapovednik' (strict nature reserve) in a semi-arid area around two notable features: Lake Baskunchak, Russia's largest undrained salt lake, and Big Bogdo Mountain, the highest point (at 147 meters) in the Caspian Depression and home to the "singing rocks".

[1][2] The reserve lies in the trough of the Caspian Depression, just east of the Volga's present main floodplain.

The main features - the shores of Lake Baskunchak and Big Bogdo Mountain, are seated about 25 meters below sea level.

The sedimentary landscape is recently exposed lake bed (during the Tertiary the Caspian Basin was connected across the Black Sea to the Mediterranean.

This climate is characterized by high variation in temperature, both daily and seasonally; with dry winters and cool summers.

Demoiselle cranes are among the migrating birds and come back every spring to mate, nest, bring up their chicks and leave again for the winter.

[6] The natural reserve is among the last places where the endangered Saiga antelopes hope to recover from being hunted close to their extinction.