Canonical
In the first book the Land of Oz is described as cut off from the rest of the world by the surrounding desert.
The central country of Baum's Oz books: geographically isolated by desert and later explicitly described as enchanted into a Fairyland by Queen Lurline.
In the first book the Land of Oz is described as cut off from the rest of the world by the surrounding desert.
Queen Lurline's fairy band enchants Oz and makes it a Fairyland.