Kaluga is a city and the administrative center of Kaluga Oblast, Russia. It stands on the Oka River 150 kilometers southwest of Moscow. Its population was 337,058 at the 2021 census.

Vorotynsk is a former town located 17 km south of Kaluga in the Ugra National Park. The town is thought to have been situated slightly downstream from the confluence of the Oka and the Ugra Rivers.