Framlingham Castle in East Suffolk

You're standing at Framlingham Castle, in the little market town of Framlingham in Suffolk. Take a look at those walls. They're built of local flint, about ten and a half metres high and over two metres thick. Count the towers: there are thirteen, all square and open at the back. What you won't spot is a big central keep. That was unusual when Roger Bigod, Earl of Norfolk, built this castle around 1200. He put his trust in the wall and its towers instead.