Alcalatén Castle, located on San Salvador Mountain in the municipality of Alcora, is an Islamic fortress with medieval architectural reforms, built between the 10th and 13th centuries.
In 1233, after the conquest of Borriana, King James I granted the castle and the title of baron to the Aragonese knight Ximén d'Urrea.
The castle, with a triangular layout, covers an area of 150 square meters. It includes a main enclosure surrounded by a patrol path, with a cistern, as well as both abandoned and inhabited areas.
At the highest point, two walls forming a right angle and topped with battlements are preserved, extending into two towers; one circular to the north and one semicircular to the south. A third tower is known to have existed, though only rubble remains from its demolition in the 15th century. The eastern section is completely destroyed. At the base of the citadel, a rectangular cistern made of mortar and stones remains, measuring approximately 4 by 10 meters. The structure is built with masonry.
The entrance is on the south side, featuring two circular towers, battlements, and a barbican-style wall.
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.