Chateau des Clées is located above the village. Built probably in the 11th century, it guarded the traffic through the Jougne Pass and collected tolls on the pass road. Les Clées is first mentioned in 1134 when Pope Innocent II tried in vain to prohibit the reconstruction of the castle.
The chapel of Les Clées was built before the 14th century and rebuilt in 1738-1740.
In 1444 the Duke Louis I of Savoy commissioned the renovations of the walls. During the Burgundian War, on 22 October 1475, Swiss Confederation troops seized and destroyed the city and castle and killed the castle garrison. Under Bernese rule there were three courts in the Les Clées district, one of which was held in the city. Nevertheless, the city gradually lost importance.
Today Les Clées Castle with the surrounding ruins and village is listed as a Swiss heritage site of national significance.
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.