Wiston Castle is a motte and bailey castle in the Pembrokeshire village of Wiston. The castle and village were founded by Wizo, a Flemish settler who was granted the land by Henry I of England after he had wrested control from the previous owner, Arnulf de Montgomery (who was in revolt against Henry). The castle was captured by the Welsh on several occasions but on each occasion it was retaken. It was abandoned during the thirteenth century when the then owner moved to nearby Picton Castle.
Wiston Castle is considered one of the best preserved motte-and-bailey castles in Wales. It is built on the summit of a hill to the north of Wiston with the motte about 9 m above the base of the ditch. Surrounding the flat top there is a shell-keep that would have been the main fortification inside which all the buildings, mostly made of timber, would have been placed. The external face of the shell-keep is polygonal, with eighteen short sections, but some of these have subsided into the ditch on the north side. The inside of the shell-keep is circular. There is an arched entrance on the south side and on either side of this there are draw-bar holes which would have been used to secure the main gate. Inside is a large, oval bailey protected by a well-preserved bank. The lord's main residence would have been inside the bailey.
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.