Fantasy and adventure in the fairy land of Ev with Dorothy Gale (from The Wizard of Oz), Princess Ozma, a wicked Nome King, an enchanted royal family and more. 111 black-and-white illustrations.
I'm sure no one will be popping into the world of Oz without having read "The Wonderful Wizard of Oz," but if one were to do so, this makes a better starting point that the somewhat disappointing second in the series.
This third book is, I think, the best of the Oz stories (which have a tendency to give in to an increasingly episodic nature and abandon storyline completely.)
Dorothy has returned to Oz, and ultimate ends up in the underground Kingdom of the Nome King (a marvelous creation), where her task is to discover whom he has transformed into chachkas, or be transformed herself (honestly, that's the plot!)
It's delightfully full of incident, the villain has real (comic) menace, and call me a heretic, but I prefer the elegant Art Nouveau illustrations of John R. Neill to the Denslow art in the first book.
Note: a 3 star ranking from me is actually pretty good; I reserve 4 stars for tremendously good works, and 5 only for the rare few that are or ought to be classic; unfortunately most books published are 2 or less.
And if you've read all the Oz books and are looking for other titles that are just as magical and just as inspired, try the Chronicles of Narnia, King Fortis the Brave or Abarat. All will introduce you to other magical worlds that are every bit as fun to visit as Oz.