North of Smolenice is the village Buková with water reservoir and a marked route, which leads southward to the romantic ruins of the Castle Ostrý Kameň from the 13th century. The Castle was a royal border fort guarding the Czech road in the past. It is in decay since the 18th century though part of its walls, bastion, and adjacent buildings are still observable. The top of the Castle provides a nice view of the Malé Karpaty Mts. and the Záhorská nížina lowland.
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.