The Peace Palace (Vredespaleis) is an administrative building and often called the seat of international law because it houses the International Court of Justice (which is the principal judicial body of the United Nations), the Permanent Court of Arbitration, the Hague Academy of International Law, and the extensive Peace Palace Library. In addition to hosting these institutions, the Palace is also a regular venue for special events in international policy and law. The Palace officially opened on 28 August 1913, and was originally built to provide a symbolic home for the Permanent Court of Arbitration, a court created to end war which was created by treaty at the 1899 Hague Peace Conference.
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.