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.
Tynemouth, UK, Tynemouth Priory on the coast of North-East England Once one of the largest fortified areas in England, this ancient building and the adjacent castle overlook the North Sea and the River Tyne.