Plavecký Castlee was built as a royal frontier castle between 1256 and 1273. Until the 16th century it was owned by Counts of Jur and Pezinok. In the second half of the 16th century the castle was rebuilt into a Renaissance style with the lower court. Gradually it was again fortified and maintained during the 17th century (new cannon towers were added then). In 1706 the castle was damaged the imperial army that conquered it from the rebels.
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.