WarningMight contain spoilers.

This is a well-respected novel but I have little to say about it except that I found it stilted, abrupt, inconsistent in its tone, and unsatisfying. I believe Cliff on the Goodreads page may have the right of it:

This book is often mentioned as having to help start the Fantasy genre. And there are comparisons to be made to Narnia. However, I've commented on this before in one of my other reviews...writing has evolved tremendously in the last 50 years, much to the detriment of this novel.