Graz old town is one of the best-preserved city centres in Central Europe. The oldest settlement on the ground of the modern city of Graz dates back to the Chalcolithic Age. However, no historical continuity exists of a settlement before the Middle Ages. During the 12th century, dukes under Babenberg rule made the town into an important commercial center. Later, Graz came under the rule of the Habsburgs, and in 1281, gained special privileges from King Rudolph I.
In the 14th century, Graz became the city of residence of the Inner Austrian line of the Habsburgs. The royalty lived in the Schloßberg castle and from there ruled Styria, Carinthia, most of today's Slovenia, and parts of Italy.
In the 16th century, the city's design and planning were primarily controlled by Italian Renaissance architects and artists. One of the most famous buildings built in this style is the Landhaus, designed by Domenico dell'Allio, and used by the local rulers as a governmental headquarters.
Graz bear witness to an exemplary model of the living heritage of a central European urban complex influenced by the secular presence of the Habsburgs and the cultural and artistic role played by the main aristocratic families. They are a harmonious blend of the architectural styles and artistic movements that have succeeded each other from the Middle Ages until the 18th century, in the many neighbouring regions of Central and Mediterranean Europe. They embody a diversified and highly comprehensive ensemble of architectural, decorative and landscape examples of these interchanges of influence.
In 1999, Graz was added to the UNESCO list of World Cultural Heritage Sites, and the site was extended in 2010 by Schloss Eggenberg.
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.