The old Dalquharran Castle consists of a ruined 15th-century tower, with a round tower at one corner. It was extended to form an L-plan, and rises to three storeys and a garret within the corbelled-out crenellated parapet. The castle was extended and altered in the late 17th century, and was surrounded by gardens and landscaped grounds. The basement is vaulted.
In the 18th century, when it was abandoned for the mansion of Dalquharran New Castle. Today the ruins of the old castle are reachable via public footpaths along the riverside, and although the castle is labelled dangerous, there is evidence of it regularly being used as a drinking den.
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.