This is a beatifully illustrated and brilliantly-written guide to England's best houses. Navigation is made easy through the useful organisation of the entries by county, and the excellent index and contents pages. Another nice feature is the ratings, where houses are given stars out of five, as if they were films, albums or books. These critical reviews are unfailingly objective and reliable, too.
The book doesn't just cover houses open to the general public (for example, Brocket Hall in Hertfordshire) and also covers such things as the occasional ruined castle (for example, Brougham Castle in Cumbria). In fact, what it does and doesn't cover is probably the only weakness of the book, becasue it seems a little random at times.