Burg Hauenstein, Medieval castle ruin in Kainach bei Voitsberg, Austria

Burg Hauenstein is a castle ruin set on a rocky outcrop near Kainach bei Voitsberg in Styria, Austria. The five-story keep is the tallest part still standing, and the site also includes three gates and several sections of stone walling.

The castle was first documented in 1222, when Wulfing von Hanau held it as a fief from the Styrian sovereigns. It was built at the end of the 12th or beginning of the 13th century to protect the trade route from the Kainach valley over the Gleinalpe to the upper Mur valley. The Hanau family held it until the early 15th century, after which ownership changed frequently. A fire around 1600 led to its abandonment.

The name Hauenstein refers to the rock on which the castle stands, and this is easy to see as you approach the site. On site, you can read the different building phases directly in the walls, as older and newer sections sit side by side.

The ruin is reached by a marked trail from Gallmannsegg, which crosses a bridge and leads directly to the castle grounds. The climb is moderate, but good footwear is helpful, especially in wet conditions.

The castle is also called Pflegerschloss after the nearby Haus Pfleger, a former meierhof north of the ruin with a hunter's house, stables, a well and a wooden chapel. A mule track and an old path partly cut into the rock lead from there up to the castle.