In the furthest reaches of Northumberland, close to the Scottish border, stands the romantic ruin of an ancient family seat. This is not a particularly unusual sight in this region of skirmishes and sackings, so why has this particular building become known as a folly? It is of course an elegant eye-catcher, seen over the single span of the ancient bridge over the river Till, but there is more to the story, and as Barbara Jones wrote, Twizel Castle falls into the ‘foolishness-type folly’ category – a picturesque but purposeless palace.