Sky Island
Sky Island is a place Trot and Button-Bright once traveled to together.
First named in The Scarecrow of Oz, ch. 8
"We made a journey together to Sky Island, once, and were good friends."
Where this is
placed Beyond the desert worked out
read out of the chapters cited on this page, not stated in any one sentence of them
Named directly in the 'nearby' world's own list of example countries reached across the desert or ocean.