Caergwrle Castle is located in the town of Caergwrle, in Flintshire, Wales. Believed to have been preceded by a hill fort, it was constructed in 1277 by Dafydd ap Gruffydd under the reward of King Edward I. The castle had notable features such as D-shaped towers and a circular keep. It was partially destroyed during Dafydd's revolt in 1282 but was restored by Reginald de Grey. Edward gifted the castle to his wife Eleanor of Castile but it suffered damage in a fire. Subsequent repairs were not made, and the castle fell into ruin. Caergwrle Bowl, an archaeological find from the Bronze Age, was discovered in the vicinity in 1823. Excavations were conducted in the late 20th century, and the castle ruins are now maintained by Caergwrle Community Council. The site is listed as a Grade I structure.
References:Ehrenbreitstein Fortress was built as the backbone of the regional fortification system, Festung Koblenz, by Prussia between 1817 and 1832 and guarded the middle Rhine region, an area that had been invaded by French troops repeatedly before. The fortress was never attacked.
Early fortifications at the site can be dated back to about 1000 BC. At about AD 1000 Ehrenbert erected a castle. The Archbishops of Trier expanded it with a supporting castle Burg Helferstein and guarded the Holy Tunic in it from 1657 to 1794. Successive Archbishops used the castle's strategic importance to barter between contending powers; thus in 1672 at the outset of war between France and Germany the Archbishop refused requests both from the envoys of Louis XIV and from Brandenburg's Ambassador, Christoph Caspar von Blumenthal, to permit the passage of troops across the Rhine.