Ипатьевская летопись
Vorotynsk (), located 17 km south of Kaluga in the Ugra National Park, was one of the Upper Oka towns and seat of the mediaeval Princes Vorotynsky. It was first mentioned in the Hypatian Codex under the year 1155. In 1480, Vorotynsk was the principal Tatar base during the Great standing on the Ugra river. The town is thought to have been situated slightly downstream from the confluence of the Oka and the Ugra Rivers.