Oberkapfenberg is mentioned in a document for the first time in 1173. The current castle was erected around 1264. It was the residence and administrative seat of the Counts of Stubenberg and the seat of the regional High Court for most of the Mürz Valley. Around 1550 it was converted into a Renaissance fortress that was abandoned in 1739 and fell into disrepair. After 1955 the Stubenberg Family rebuilt their ancestral fortress within the old walls and adapted it into a castle hotel. Today Burg Oberkapfenberg is a cultural and culinary attraction of more than regional importance.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.