You could look for a location where you have a view over a large river valley, with an object such as a bridge in the middle of the valley, and hills which are higher than the bridge on one or both sides.
Stand or sit on one side at the same height as the bridge tower, with a view to the higher hills beyond.
Let's say your height, and the height of the bridge, is 2 units, and you have hills beyond which are 4 units high.
Does the sightline from you, at 2 units high, through the top of the bridge, also 2 units high, meet the hills beyond at exactly the 2-unit elevation?
Let us all know once you've done this, and we can then compare notes.