Grodno Castle (formerly Kynsburg) is a castle located in the southern parts of the Wałbrzych Mountains, on the Choina Mountain (450 metres), standing to the left of the river Bystryca. The valley of this river, formerly known as the Silesian Valley, creates a natural boundary between the Owl Mountains and to the west of it the Wałbrzych Mountains. The castle is located in Zagórze Śląskie (11 km east of Wałbrzych), Lower Silesian Voivodeship in Poland.
The picturesque location of the castle is exacerbated by the barraged Lubachowskie Lake in the foothills of the mountain.
According to tradition the castle was built in 1193, by Duke Boleslaw I the Tall. The castle, together with a network of fortresses was used as a defense line between the Duchy of Jawor and the Kingdom of Bohemia. In the sixteenth century Grodno Castle was expanded by a gatehouse, on which there is precious sgraffito, and a sundial clock from 1716. The castle was devastated in battles against the Swedes during the Thirty Years' War, slowly falling into ruins. In the nineteenth century the tower had collapsed. The last owner of Grodno, was the Zedlits family, which had continued renovation works and strengthened the castle
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.