Lilleborg is a ruined castle in the Almindingen forest. The castle was probably built in the middle of the 12th century as a royal fortress. It appears to have replaced the much larger fortress of Gamleborg which was only 700 metres away. The move could be explained by the fact that in 1149, three-fourths of Bornholm had been surrendered to Eskil, archbishop of Lund. As a result, King Sweyn III wanted to establish his own seat of power on the remaining fourth of the island. While it could not be compared to the archbishop's Hammershus, Lilleborg was nevertheless a fine stronghold and appears to have been easier to defend than the much larger Gamleborg. There is evidence suggesting the fortress burnt down in 1259 when Prince Jaromar of Rügen stormed and destroyed the 'king's stronghold' on Bornholm. However, coins minted after that date have been found, indicating it was inhabited after its storming.
Lilleborg's construction inland rather than on the coast has been compared to that of Refshaleborg on Borgø in Maribo lake. It had a large tower, 9.5 metres square, protecting the entrance to the courtyard. Its walls were 2.4 metres thick and from the top it was easy to hit anyone trying to attack. The fortress is further protected by a curtain wall which follows the cliff tops around the oval plateau. The interior was some 76 metres long and 41 metres wide. When its defenses were obsolete, the fort's stones were re-purposed for other buildings. From 2006 to 2011, restoration work was carried out at Lilleborg.
References:Trenčín Castle is relatively large renovated castle, towering on a steep limestone cliff directly above the city of Trenčín. It is a dominant feature not only of Trenčín, but also of the entire Považie region. The castle is a national monument.
History of the castle cliff dates back to the Roman Empire, what is proved by the inscription on the castle cliff proclaiming the victory of Roman legion against Germans in the year 179.
Today’s castle was probably built on the hill-fort. The first proven building on the hill was the Great Moravian rotunda from the 9th century and later there was a stone residential tower, which served to protect the Kingdom of Hungary and the western border. In the late 13th century the castle became a property of Palatine Matúš Csák, who became Mr. of Váh and Tatras.
Matúš Csák of Trenčín built a tower, still known as Matthew’s, which is a dominant determinant of the whole building.