Vorotynsk (Russian: Вороты́нск) 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 base of Russian operations against the Tatars 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.
The village of Spas-on-the-Oka, which now marks the spot, is dominated by Saviour Vorotynsk Monastery, founded by one Prince Vorotynsky in the early 16th century. This long-deserted cloister is noted for two crumbling churches with pyramidal roofs, one dating from the 1560s, and another from the 1640s. There are also two villages, New Vorotynsk and Old Vorotynsk, located just south-west from the modern town of Kaluga.