Gamberk Castle, Medieval castle ruin in Ržiše, Slovenia.

Gamberk Castle is a fortification ruin perched on elevated terrain in the Zagorje ob Savi region, where stone foundations and wall remnants remain visible. The site contains traces of defensive barriers and gate structures that hint at the scale of its former stronghold.

Gamberk is first documented in 1248, when Wilbirge, daughter of Konrad Gall zu Gallenberg, issued a deed; the castle was probably built in the late 12th or early 13th century as the seat of the Gallenberg family. The claim that Ortolf III. von Scherfenberg built it is not supported in writing. In the early 15th century it passed to the von Sternberg, who sold it to the Habsburgs in 1443. From 1553 Jacob von Lemberg had it rebuilt in the manner of a palace.

The name Gamberk is the Slovene form of the German Gallenberg, after the noble family that held the castle as its seat. Below the gate passage the society has mounted information boards, and a Baroque double coat of arms with a motto ribbon survives in the ruins. In front of the entrance stand a gavge and a pranger, the medieval devices lords used to discipline disobedient peasants.

The ruins are reachable via marked hiking paths starting from the nearby village of Ržiše, which serves as a convenient base. Visitors should wear sturdy footwear and expect uneven terrain, as the paths traverse hilly landscape.

The castle was built beside the old trade route from Ljubljana through Moravče and Marija Reka into the Savinjska dolina, so its position controlled traffic as much as it watched the valley. The hill itself was declared a natural landmark in 1993 for its geological, geomorphological and botanical features.