Ran across this site which contains the author's views as to the locations featured in Piper's novel, Lord Kalvan of Otherwhen. He's gone around, and gathered an impressive array of photographs of the sites which he thinks matches the locations described in the novel. Some of the photos are quite pretty. Overall, it's the sort of thing you'd expect of a Civil War buff researching an obscure campaign, not a fan of a forty-year-old science fiction novel. I am impressed by his fannish dedication to detail.