Which Russian lake is Europe's second-largest lake, after Lake Ladoga?

Lake Onega is Europe’s second-largest lake, after Lake Ladoga, and it lies entirely in northwestern Russia. Its basin extends across the Republic of Karelia, Leningrad Oblast, and Vologda Oblast.

The lake covers approximately 9,891 square kilometers and belongs to the Baltic Sea drainage basin. Around 50 rivers flow into it, including the Shuya, Suna, Vodla, and Vytegra, while the Svir River carries water westward toward Lake Ladoga. That connection places Onega within a major chain of waterways linking Russia’s interior with the Baltic.

Lake Onega is also notable for its many islands—more than 1,300 are commonly listed—and for Kizhi Island, home to the celebrated Kizhi Pogost architectural ensemble. Petrozavodsk, the capital of Karelia, stands on its western shore. A frequent mistake is to select Lake Peipus: Peipus is a large transboundary lake, but it is smaller than Onega and is shared by Russia and Estonia.