Monteserico Castle is situated on a hill in a strategic position for controlling commercial traffic on the Appian Way that passed nearby. First documented in 1041, the year of a famous battle between the Byzantines and the Normans, it became a domus during the Swabian period and a royal farmstead under the Angevins. The Monteserico Castle communicated with the Garagnone Castle and the Gravina Castle (commissioned by Frederick II) through signal torches to alert of approaching enemies.
Destroyed in the early 1500s, it underwent restoration in several phases from the 18th to the 19th century and has recently been the subject of restoration efforts.
In 1989, the municipality of Genzano di Lucania acquired ownership of the building.
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.