Lierna Castle is built on a peninsula that protrudes into the lake Como and consists of a group of connected buildings, rather than a single building. The main portion of the current buildings was constructed in the 10th century in Romanesque style upon former Roman ruins. The castle includes the 11th-century church of Saints Maurice and Lazarus (Chiesa dei Santi Maurizio e Lazzaro), associated with the Order of Saints Maurice and Lazarus.
The last military use of the castle was in the mid-16th century by Gian Giacomo Medici, known as 'Medeghino' (the 'small Medici'), who was primarily a mercenary.
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.