Situated on the left bank of the Navia Estuary, Castro de Coaña is a hilltop settlement (4th Century BC) surrounded by walls and accessed from the south. The main defensive structure is located precisely in the south and consists of a wide ditch dug into the slaty subsoil finished off by a wall. Inside, the settlement is divided into several sectors.
It has a diamond shape in which the three areas can be clearly distinguished. The acropolis is a triangular enclosure surrounded by a wall, not used for housing. Access to this area was protected by a square tower. The northern residential sector spreads out beneath the north wall of the acropolis, mostly consisting of circular huts. Some of them are accessed via a hall or corridor. The walls are made of slate with rounded corners.
Inside the residential sector near the gate to the acropolis, there are two groups of buildings associated with channelling water and a pool, a granite vessel called a 'bath', which suggests that it was used for bathing or rustic saunas.
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.