Rocannon's World

Rocannon's World is Ursula K. LeGuin's first novel, published in 1966 as a lengthening of the story "Dowry of the Angyar," which appeared in Astounding in 1964 and comprises the prologue to the novel as "Semley's Necklace". It's currently out of print, but I found it in a used book store in Seattle and there are some used on the internet as well. It is basically an epic fantasy set in a world of relativistic interstellar travel, in which an anthropologist studying quote highly intelligent life forms (a hilfer) from the galactic league of worlds is stranded on Fomalhaut II, an alien world with a heroic early age culture (think Homer) that involves living in castles and riding giant flying cats (see cover). Our boy Rocannon has to journey across the planet with a motley band of locals (think Tolkien), seeing the sights and getting into various problematic situations along the way. It's not her most mature work, but in particular the way in which she incorporates relativistic travel into the epic register is pretty impressive. Plus, giant flying cats are sweet.