The Wall was inspired by Martin's visit to Hadrian's Wall, in the North of England close to the border with Scotland. Looking out over the hills, Martin wondered what a Roman centurion from the Mediterranean would feel, not knowing what threats might come from the north. This experience was so profound that a decade later, in 1991, he wanted to "write a story about the people guarding the end of the world", and ultimately "the things that come out of the north are a good deal more terrifying than Scotsmen or Picts".