The Arab Baths of Jaén (Baños Arabes de Jaén) are a well-preserved historic hammam (Islamic bathhouse). The bathhouse dates from the 11th century during the Taifa or late Caliphal period, but may have undergone later alterations, probably in the 12th century. It is one of the largest known examples of Andalusi bathhouses, and is distinguished from others by its particularly large 'warm room' (bayt al-wasti).
Following the Christian conquest of the city by Ferdinand III in 1246, the baths remained in use for a while until they were repurposed as tanneries. In the 16th century Don Fernando de Torres y Portugal (Count of Villardompardo and Viceroy of Peru) built himself a private palace on top of the baths, thus hiding them for centuries. They were only definitively rediscovered by Enrique Romero de Torres in 1913 during a survey of historic buildings in the city. Archeological studies later followed and the site was declared a Cultural Heritage Property of Spain in 1931. Today it is open to visitors as a historical attraction as part of the Palacio de Villardompardo.
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.