Sky Island: Being the Further Adventures of Trot and Cap'n Bill after Their Visit to the Sea Fairies is a children's fantasy novel written by L. Frank Baum, illustrated by John R. Neill, and published in 1912 by the Reilly & Britton Company—the same constellation of forces that produced the Oz books in the first decades of the twentieth century.As the full title indicates, Sky Island is a sequel to Baum's The Sea Fairies of 1911.