Kozjak Castle

Kozjak Castle is a historic ruin situated on a rocky hill above the village of Dolenje Selce, near Dobrnič in the Municipality of Trebnje, Lower Carniola, Slovenia. Constructed after 1250, this medieval fortress was first documented in 1332 as castrum Cozyak, though historical records suggest the knight Ulrik of Kosieck owned the site as early as 1274. Originally part of the Šumberk lordship, it became the seat of the Kosieck knights and the center of its own distinct lordship under the influence of the Counts of Gorizia. The architecture, famously depicted in Johann Weikhard von Valvasor's 1689 etching, featured a rectangular two-story main building with a large southern extension, an elevated eastern platform, and protective external walls reinforced by three towers.

The castle possesses a dramatic history marked by the tragic fate of its last native lord, Louis of Kosieck. In 1475, he was captured by Ottoman forces and held for ransom. Although his family secured his release a year later for 2,000 guilders, Louis died shortly after returning home, allegedly poisoned by his captors. Following the extinction of the Kosieck line, ownership passed to the Sauer family and later to the Räuber and Auersperg noble houses. By the late 17th century, the structure began to decay as sections were abandoned, a process that continued until the early 19th century left it a complete ruin described as an overgrown pile of rocks after World War II.

Today, Kozjak Castle stands as a preserved archaeological site where visitors can observe the remaining outer walls and central building. While the roof and upper stories are long gone, the basic floorplan, room remnants, and tower foundations remain clearly visible, offering insight into its original layout. Beyond its physical presence, the castle holds cultural significance as the primary setting for Jurij Kozjak, a renowned novel by Slovene writer Josip Jurčič. This literary work vividly portrays medieval life within the castle walls during the era of Ottoman incursions, ensuring the site's legacy endures in national memory despite its ruined condition.