The Torre Monreal is a tower, traditionally considered of Arab origin, located on a hill to the southwest of the city of Tudela.
It probably dates from when Amrùs walled Tudela in the year 802. However, there is no documents before the thirteenth century. In 1343 the ramparts and battlements of the tower were repaired, as they were demolished in the severe storms and floods that occurred in previous years. After the Castilian conquest of the Kingdom of Navarre at the beginning of the 16th century and the dismantling of the walls and defenses of Tudela (especially from 1521), the Torre Monreal lost its defensive character, being enabled for other purposes.
The Torre Monreal has been subsequently rebuilt on various occasions. It served as a fortress for the French after the invasion of Spain and Navarre, and was demolished by Espoz and Mina in 1813 , at the end of the War of Independence. It was rebuilt in 1883 , for the defense of the city during the Carlist Wars. The current octagonal brick construction is, therefore, from the Carlist period.
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.