The typical Galician noble fortress in Castro Caldelas with medieval origins has been splendidly conserved and restored and today functions as a library, cultural centre and exhibition venue.
The castle originally belonged to the House of the Counts of Lemos, and became part of the House of Alba in the 18th century. It was built in the 14th century as a fortress with a purely military function, and was renovated in the 16th century and converted into a palatial residence.Its floor plan is in the shape of an irregular polygon, as it adapts to the hill on which it stands. It comprises several parts or buildings, of which the rectangular keep and the clock tower are the oldest. Other surviving elements include the bailey, sections of the defensive wall, three square towers, the administrator's house, the palace (containing the library, a museum about the castle and other rooms), the interior sentry walk and the outer moat.
The location of the castle, on top of a mountain, also provides some panoramic views of the valleys below and it is easy to appreciate how impenetrable this town must have seemed to past aggressors.
You enter the castle (free of charge) through the main gateway and once inside you have unlimited access to all areas including the battlements.
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.