Acaya Castle wa built by the Knight Alfonso of Acaya in around 1506. In the following years, his son Gian Giacomo dell'Acaya, a famous architect, rebuilt the entire complex, transforming it into a fortified hamlet and making it the main centre of his estate. He also renamed it Acaya. After his death in 1570, the hamlet was sold and Acaya began to decline slowly, until its rebirth in the 20th century.
The Castle, which has a trapezoidal base, is accessible through a single bridge. The fortified walls are reinforced by two cylindrical towers. A stairway leads up to the rooms on the upper floor, including the bastion hall, with its painting of the Spanish Kings' coats of arms, and a room decorated with classically-styled motifs carved in Lecce stone.
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.