Valencia Cathedral was consecrated in 1238 by Pere d'Albalat, Archbishop of Tarragona, and was dedicated to Saint Mary by order of James I the Conqueror. It was built over the site of the former Visigothic cathedral, which under the Moors had been turned into a mosque.
Most of Valencia Cathedral was built between the 13th century and the 15th century, and this style was mainly Gothic. However, its construction went on for centuries. As a consequence there is a mixture of artistic styles, ranging from the early Romanesque, Valencian Gothic, Renaissance, Baroque and Neoclassical.
The cathedral contains numerous 15th-century paintings, some by local artists (such as Jacomart), others by artists from Rome engaged by the Valencian Pope Alexander VI who, when still a cardinal, made the request to elevate the Valencian See to the rank of metropolitan see, a category granted by Pope Innocent VIII in 1492.
A purported Holy Chalice, believed by many to be the true Holy Grail, is revered in one of the cathedral's chapels. It has been the official chalice for many popes. This chalice with Arabic inscriptions dates from the 1st century, and was given to the cathedral by king Alfonso V of Aragon in 1436.
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.