Ribnica is an Ottoman fortress, located in the Stara Varoš neighborhood of Podgorica, the capital city of Montenegro. The fortress was built in late 15th century (around 1477), during the period of Ottoman reign. It was built above the confluence of Ribnica and Morača rivers, and was one of two fortresses surrounding Stara Varoš.
For a long time, Depedogen was used as an ammunition warehouse. It was severely damaged in 1878, when a thunder strike triggered an explosion which destroyed a large part of the fortress's interior and exterior.
A legend commonly told by the Serbian Orthodox Church leaders says that the fortress stems from the 12th century, and that it's the birthplace of Stefan Nemanja - the founding father of the Nemanjić dynasty. Therefore, a lot of people call the fortress Nemanjin Grad or Nemanjića Grad (Nemanja's Town) and Orthodox ceremonies are often held at the location.
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.