Fort Punta Christo was built at the end of the 19th century by the Austro-Hungarian Monarchy to defend City of Pula, their main naval port. Situated on a small peninsula at 45 meters above sea level, Fort Punta Christo offers a breathtaking view of the entrance to the Bay of Pula, its breakwater, as well to National Park Islands Brijuni on the other side. The fortress is surrounded by a deep ditch and there are three entrances leading to the fort. Inside the fort are three courtyards through which you can enter the underground areas of this magnificent structure. The fortress has as many as 270 spaces, covering an area of over 10,000 m2.
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.