22S 20E on the Namibia - Botswana border

I am indebted to Hardy Burmester for this excellent aerial photograph, taken from a glider, showing the point at 22 S 20 E.  This clearly shows the fence which makes a right-angle at this point, as well as the road on the Namibian side which takes a bend around the apex.  The fence itself is simply a wire fence.  What is visible from the air is in fact the slightly different vegetation on both sides of the fence, as well as the tracks made by patrolling vehicles.

You can see that the two lines, 22 S and 20 E, are continued on the Namibian side.  These are not fences or roads, but rather  "Strip Lines" or "Cut Lines", where all the vegetation has been cleared to provide a major reference line over a long distance. You can drive along these lines in a 4x4 vehicle, but have to be careful of soft sand, holes, rocks, tree trunks, etc...

The other fainter lines are farm fences. Once again, what you see is the slightly different vegetation along the fence lines.