The Seville Shipyard (Atarazanas) is a medieval shipyard. It was operative between the 13th and 15th centuries, and are built in Gothic style.
They were specialized in the construction of galleys, which played an important role in the struggles for the control of the Strait of Gibraltar, as well as in the Castilian participation in the Hundred Years' War. The complex consisted of a building with seventeen naves next to a large sandy area that reached to the edge of the Guadalquivir River.
Throughout its history, the building of the Royal Shipyard has undergone important transformations. At present, only seven of the seventeen original naves remain standing.
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.