Střekov Castle (Schreckenstein) is perched atop a cliff above the River Elbe, near the city of Ústí nad Labem. It was built in 1316 for John of Luxembourg, the father of the Holy Roman Emperor Charles IV, to guard an important trade route to Germany. After changing hands several times, the castle was acquired by the Lobkowicz family in 1563. Its strategic importance led to occupations by Imperial Habsburg, Saxon, and Swedish forces during the Thirty Years' War, as well as successive sieges by Austrian and Prussian armies during the Seven Years' War.
Although Střekov Castle was heavily damaged during those conflicts and abandoned as a military installation by the end of the 18th century, the 1800s saw many poets and artists visiting the castle, drawn by a new trend of interest in romantic ruins. Goethe declared the view from the castle's position above the Elbe to be the most beautiful in Central Europe, while Richard Wagner's opera Tannhäuser was supposedly inspired by his visit to Strěkov. The castle was confiscated by the Nazi regime and later the Communist government, but was restituted to the Lobkowicz family in the early 1990s.
Střekov Castle is divided into two sections connected by an arched bridge spanning a natural moat— an unusual style for the 14th century, when it was first built. The castle’s semiround bastions, inspired by French architecture, are possibly the first example of that type of defensive design in Bohemia. The connecting round tower, a smaller tower guarding the castle entrance, and an irregular oblong section of the castle date back to the very earliest period of construction.
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.