The town of Buitrago del Lozoya is completely surrounded by an ancient wall originally built by the Moorish people. Within these walls lies the ruins of the Buitrago de Lozoya castle. The style of the castle is a unique mix of Mudéjar (moorish) and Gothic designs – tall, solid square towers combined with the typical pentagonal shaped often used by the ancient Arabs. It was built in the 15th century. It has a rectangular plan, with seven towers of various shapes (round, pentagonal, square), all in stone. The interior is in ruins.
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.