In my story, the character will walk to a space elevator he can see far away, but the question is "from how far away can he see his destination"?
The action is happening is inside a gigantic ring of mountains, with all land between the mountain and the elevator being almost perfectly flat and at sea level. How far could the bottom of a mountain be for you to still see the elevator?
The size of the shaft can be what you want to make the visibility better, as long as it is always of the same width.