The Fortress of Brod was constructed between 1715-1780 by the Archduchy of Austria to create a defense against the Ottoman Empire. The city of Slavonski Brod was an important strategic and traffic center controlling the border crossing towards Turkey and connecting main commercial trails at the time. The regular star-like form of the fortress was determined by the flat-country. It was built of rammed earth, bricks, wood and partially stone, and designed for the accommodation of 4,000 soldiers, mostly infantry and 150 cannons.
The Fortress of Brod was constructed according to the Vauban system. It is basically of a rectangular form, while the system of defense channels provides its star-like layout. It consisted of three defense zones: internal, external and southern, and it was protected by two moat areas, water-fed from the nearby stream.
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.