Conwy Castle, Wales, is one of the most prominent fortresses built by Edward I in the 13th century. It is one of the key castles of the king's "iron ring" of fortresses constructed in Wales. The stronghold was quite an expensive undertaking - it is estimated that Edward spent £15,000 (£162 million in 2009) on the construction, which makes it the most costly castle in the Welsh history. Today Conwy is declared a World Heritage Site.
Warkworth Castle, England The original motte & bailey castle was built in the mid 12th century by Earl Henry of Northumberland, son of David I, King of Scots. In 1157, Henry II recovered Northumberland from the Scots, & in the following year gave Warkworth Castle to Roger FitzRichard. But the castle is most famously associated with the Percy family, who acquired the castle in 1332.The Percy family were one of the most powerful in the country, controlling much of Northern England.