This book is a very good source of harmless amusement for those interested in fantastic places, and the consequences of the fantasy put on them by the writers of all ages.
The authors have made varied selection of imaginary places, and have even engaged an engraver to put face to many of them (very good drawings, that look very much like those one can find in a XIX century book). Thus, the reader can find very good excepta of places such as Utopia, Oz, etc. So far, so good. One can read no place upon place, their strange customs, their peculiar leaders, etc.
The less likable part is that the constraints set by the authors leave some good places. The authors don't include places that are clearly actual places (like Brideshead) or places not to be found on Earth (like those created by sci-fi authors). Thus, their collection is somewhat restricted to older authors, like Rabelais. There's also a very ample reference to Middle Earth, which I find somewhat too extensive, because any LOR fan surely know those places by heart. Some other modern references, then could be more expanded: there's a reference to Hogwarts, but very little else concerning the JK Rowling universe or the Mortal Engines or other sci fi classics like HG Wells, etc.
Good book, worth buying, but somehow I had expected something funnier from Mangel (his History of Reading is a true, delightful masterpiece)