Cecilienhof Palace was built from 1914 to 1917. Emperor Wilhelm II ordered the establishment of a fund for constructing this new palace at Potsdam for his oldest son, Crown Prince Wilhelm (William) and his wife, Duchess Cecilie of Mecklenburg-Schwerin on 19 December 1912. Cecilienhof was the last palace built by the House of Hohenzollern that ruled the Kingdom of Prussia and the German Empire until the end of World War I. It is famous for having been the location of the Potsdam Conference in 1945, in which the leaders of the Soviet Union, the United Kingdom and the United States took important decisions affecting the shape of post World War II Europe and Asia. Cecilienhof has been part of the Palaces and Parks of Potsdam and Berlin UNESCO World Heritage Site since 1990.
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.