Pieniny Castle (Polish: Zamek Pieniny), also known as the Castle of St. Kinga, is a ruined medieval Polish castle located near Krościenko nad Dunajcem, Lesser Poland Voivodeship, in the Pieniny mountains.
The stronghold was most likely built in the early 1280s. Its construction is associated with Saint Kinga, who is believed to have commissioned it as a refuge for the Poor Clares' monastery in times of conflict. The duchess and the nuns took shelter there during the third Mongol invasion of Poland.
The castle's subsequent 14th-century history is poorly documented. While recent research suggests that it remained in use in the 15th century, the prevailing view among researchers holds that it was likely abandoned in the 14th century and destroyed during the invasion of the Hussites or the forces of Stibor of Stiboricz at the beginning of the 15th century.
The building is one of the oldest brick castles in Poland and is an example of high-mountain castle architecture. It could accommodate a hundred people and several dozen soldiers. Designed to blend into the natural landscape, the castle was fortified by impassable rocks and located at a high altitude, making it difficult for the enemy to spot.