Today is the publication date for The Ordnance Survey Puzzle Book (Trapeze), a collection of map quizzes and puzzles—a “mix of navigational tests, word games, code-crackers, anagrams and mathematical conundrums” contrived by Gareth Moore—based on some 40 Ordnance Survey maps dating as far back as 1801. It’s out in the U.K. only; North Americans will have to try third-party sellers on Amazon (or elsewhere) or order directly from British vendors.