Montgomery Castle (Cadw)

Perhaps it’s something to do with its location, on a steep crag above a pretty Georgian town with all-seeing views across the Welsh border. Commenced around 1223 on the orders of Henry III in response to the growing power of Welsh native prince Llywelyn ap Iorwerth (Llywelyn the Great), Montgomery’s stone castle replaced a nearby wooden fort known as Hen Domen. Perched on its rocky ridge, this new fortress was significantly sturdier and more sophisticated, with a stone inner ward, well, deep defensive ditches crossed by drawbridges and walled town.
The castle remained in use for centuries, surviving attacks by Llywelyn in 1228 and 1231 and Llywelyn’s son Dafydd in 1245. The castle’s ultimate end came during the Civil War, when it fell to the Parliamentarians and was demolished in 1649, leaving just the crumbling towers and low walls that stand today.