The old town of Avigliana is one of the most significant in Piedmont, for its medieval architecture and its churches. The castle was probably built in 942 by the Marqueses Arduinici of Turin (it was probably Arduino the Hairless who built the first settlement of Castrum Avilianae) on the top of Mount Pezzulano. This castle was used by the Counts of Savoy at least from 1137. In 1691, after conquering it, the French Marshal Catinat got it definitively demolished, leaving the remains we can see after a pleasant walk from Piazza Conte Rosso.
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.