Kostel Castle

The castle's origins date back to the 13th century, when the Counts of Ortenburg, vassals of the Patriarchate of Aquileia, expanded a smaller fortification into a castle between 1247 and 1325. First mentioned in 1336 as "castrum Grafenwarth," it received its current name "Costel" – a derivation of the Latin "castrum" for fortress – in 1449. After the extinction of the Ortenburgs in 1418, ownership passed to the Counts of Celje. They expanded the castle into a fortress and named it "Schloss Grauenwarth," while the surrounding settlement retained the Slavicized name Kostel. Under Frederik II of Celje, the castle and settlement were surrounded by a two-meter-thick wall and five defensive towers. The castle served to defend the possessions in Carniola, housed a local judiciary, and had its own execution site.