Ten castles, including two that are not European, get the Biesty treatment, with full-spread, minutely detailed aerial views featuring cutaway sections and antlike swarms of residents. Smaller drawings on following pages serve as visual keys to the locations of a dozen or more rooms or other parts of each structure; Hooper fleshes out those keys with glimpses of workers or visitors, most of the latter historical figures, and pivotal events in each castle’s history. Portrayals of life in fanciful or composite castles, of which Biesty’s own Cross-Sections Castle (1994) is the most spectacular, are not hard to find; here the connection with castles that still exist—though some, the author notes, are in ruins—adds an extra dimension. Fine fare for young armchair travelers, who would otherwise never get a gander at Osaka Castle, Neuschwanstein, and Castel Sant’ Angelo in their prime. (Nonfiction. 9-11)