Czersk is a settlement in the administrative district of Gmina Gora Kalwaria, within Piaseczno County, Masovian Voivodeship, in east-central Poland. It lies approximately 2 kilometres (1 mi) south-east of Gora Kalwaria, 19 km (12 mi) south-east of Piaseczno, and 33 km (21 mi) south-east of Warsaw. The village also lies on the Czersk Lake (size: 9 hectares), which is Oxbow lake of the Vistula.

In the 11th century, during the reign of either Boleslaw Smialy or Wladyslaw Herman, a wooden gord existed in the location of the castle. The gord later became administrative center of the Duchy of Czersk, mentioned in 1224 in the documents of Castellan of Czersk, Piotr Pilch. In 1229, Duke Konrad Mazowiecki imprisoned here Duke Henryk Brodaty, who was kept in the castle’s dungeon. In 1239, Konrad imprisoned here another Duke, Boleslaw Wstydliwy.

In 1350, the gord was partly destroyed in a Lithuanian raid, and in 1388, Duke of Mazovia Janusz I of Warsaw ordered conctruction of a Gothic castle with two towers and a tower gate. The castle became one of main residences of Janusz I; it was here that he died on December 8, 1429.

In 1526, Mazovia was incorporated into the Crown of the Kingdom of Poland, and the Czersk Castle became a royal property. In 1547, it was administered by Queen Bona Sforza, who in 1549 built here a residence, called Wielki Dom. The castle was almost completely destroyed in 1656, during the Swedish invasion of Poland. In 1762–1766, the Starosta of Czersk and Crown Marshall tried to rebuild the complex, as he planned to place here archives and local court. His plans failed due to the Partitions of Poland, and the castle now is a permanent ruin. It is open to visitors, who admire the preserved walls and three towers. Inside the complex, there are foundations of St. Peter church.

Best view in original size