The ruins of Illens castle stand on a rock wall above a loop of the Saane river. The castle stands on the opposite side of the river from the fortified town of Arconciel. The two castles secured both sides of a crossing (either a ford or a bridge) over the river. The castle is first mentioned between 1150 and 1276.
In 1366, the notoriously violent Count Peter of Aarberg moved into the castle and remained there for a short while. The chamberlain of Charles the Bold, Guillaume de la Baume, expanded the castle and when he left in 1470, it was an elegant and comfortable palace. During the conflicts leading up to the Burgundian Wars, Fribourg and Bernese troops stormed and damaged the building on 3 January 1475.
In 1900, it was partly repaired and expanded and served a community of Trappist monks.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.