Open since 1936, Heywood Hill is considered by some to be the best small bookstore in the English-speaking world—John Le Carré, who set a scene in Tinker Tailor Soldier Spy here, is a long-standing customer. Here's where you can pick up a leather-bound volume on architecture, gardening, natural history, and topography—just some of the topics in which the antiquarian collection specializes. The contemporary selection emphasizes literature, history, biography, travel, architecture, and children's books. During World War I, author Nancy Mitford helped keep the bookstore going. Today, the 12th Duke of Devonshire, a descendant of her brother-in-law, the 11th Duke, is the owner.