The world of Middle-earth that Tolkien created is incredibly expansive, even just within the continent itself. The Lord of the Rings storyline takes place in Middle-earth, but there are references throughout Tolkien's writing to places that exist outside of it. Middle-earth is huge, but is there more to Tolkien's world than just that one continent? The answer is yes, but since these other areas don't factor into the Lord of the Rings story very much, not a lot is known about them.