The town of Atripalda is the home of the ruins of Abellinum, the Ancient Roman Avellino. A large than life-size Roman marble statue of a veiled priestess from Atripalda can be found in the British Museum's collection.
Before the Roman conquest, the Abellinum was a centre of the Samnite Hirpini. The city could correspond to the ancient Velecha, documented by coins found in the area. Abellinum was conquered by the Romans in 293 BC, changing name several times in the following centuries (Veneria, Livia, Augusta, Alexandriana, and Abellinatium). However, the construction of a true Roman town occurred only after the conquest by Lucius Cornelius Sulla in the civil wars in 89 BC. He razed the old site and in 82 BC founded the colony Veneria Abellinatium on the left bank of the river Sabato.
The new city was surrounded by massive walls and had an orthogonal hippodamian urban layout. In 7 AD Augustus changed its name to Livia Augusta in honour of his wife, Livia Drusilla who owned the territories between Abellinum and Aeclanum. In the 3rd century Alexander Severus expanded the colony under the title of Livia Augusta Alexandrina with a massive immigration of oriental settlers. This helped to spread ancient Levantine cults such as Sol Invictus in the territory.
There followed economic crises (III and IV centuries), violent earthquakes (346) and disastrous volcanic eruptions (472). The town was Christianised around 500, becoming an episcopal seat.
The ruins include the forum, faced by temples, baths, parts of the Serino aqueduct and a patrician domus. There was also an amphitheatre and a brothel.
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.