Yarmouth Castle is located on the eastern side of the River Yar estuary on the Isle of Wight and was built by King Henry VIII in around 1547 to protect the island from invasion by the French. The French had landed on the Isle of Wight briefly a couple of years earlier and it was probably this event that Henry has reacting to. It is one of a series of gun-forts that Henry had built to protect the whole of the south coast. Hurst Castle, another of Henry's gun-forts is located on the other side of the Solent. Like other gun-forts built at the time, Yarmouth Castle was designed not as a residence but as a platform to hold large guns, but its shape is completely different. While most of the other gun-forts had a circular central tower, Yarmouth Castle has a square tower with 100 feet long sides.

arthwork remains of a motte and bailey castle near the village of Yielden in Bedfordshire. Mound with two baileys. Unsure if this is on private land.

Ystrad Meurig Castle is located inland around eleven miles to the south east of Aberystwyth on the west coast of Wales. Documents relating to the castle could refer to another small castle a short distance to the east. First mentioned in around 1116 and again in around 1136 or 1137 when one of the sites was attacked. The castle was rebullt in 1151 and last mentioned in around 1208. The current site consists of a natural area of higher ground with earthworks. To the south the natural falling off of the land was used as a defence while to the north a ditch was dug. At the centre are the foundations of a large square keep.