Before I get to the main subject of this post, I have a question: How did it happen that Thor: The Dark World ended up with the exact same plot as the second season of Legend of Korra? Both have a (Harmonic) Convergence returning after thousands of years, a Dark Elf (Thor)/ Dark Spirit (Korra) that wants to bring the world into darkness, essentially destroying it, a mistake by a main character that makes this possible, etc., etc. I like both stories, but this is seriously weird.
So. On to King Solomon's Mines. This book is by H. Rider Haggard, was written in the Victorian Era, and was recommended by C. S. Lewis. It concerns an elephant hunter named Allan Quatermain who is hired to help a fellow Englishman find his brother, who has apparently gone in search of the legendary mines of King Solomon. I will not go through the plot in detail. Much of it is standard "adventure with primitive tribes" stuff, though I gather that this book is one of the reasons some of these things became standard. (The book's solar eclipse, for example, is clearly borrowed for the Tintin comic book Prisoners of the Sun, and Wikipedia informs me that this book was a major influence on 1930s Republic adventure serials--which of course inspired Indiana Jones.) There are also the sort of regrettable racial and colonial attitudes one might expect to find in much Victorian literature (though Haggard does have his main character explicitly reject the use of the term "nigger").
The book intrigued me early on with its description of the legend, and the ancient Portuguese manuscript--written, of course, in blood--in which a dying man tells of the riches and dangers to be found in a hidden African kingdom. Then for some time I wondered what Lewis had liked so much. The events that follow are enjoyable and exciting, but it is not till the book nears its climax that I understood what made the book so great. What had been hinted at earlier in the book comes to full flowering in the journey to the actual mines and to the Place of Death: a sense of ancient awe and mystery, a feeling that cannot be put into words, but only created by reading the words of Haggard. For that reason, this book is a great accomplishment.