Ewloe Castle is a native Welsh castle built by the Kingdom of Gwynedd near the town of Ewloe in Flintshire. The castle, constructed in the early 13th century, was one of the last fortifications to be built by the native Princes of Wales, was abandoned at the beginning of the invasion of Wales by Edward I in 1277. Its construction, using locally quarried sandstone, appears to have continued piecemeal over many years and may have not been completed. On taking the castle, the English Crown gave it little military value and allowed it to fall into ruin. The last known mention of Ewloe Castle dates back to 1311.
Ewloe Castle combines features from both motte-and-bailey and enclosure castles. An asymmetrical curtain wall – with parapets – encloses two courtyards. A rock-cut neck ditch defends the southern side of the castle. In the upper triangular inner ward is a D-shaped tower known as the 'Welsh keep'.
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.