Navigation is sooooo accurate and reliable that a waypoint can literally be a blade of grass in a field, as opposed to, say, a country mansion, or the Peheim Mast, or even the Shobdon magnet.
The Shobdon magnet - do tell? Did my PPL out there back in the '70's. Thought we only had to beware some folk to the south when we went off on early X country Nav Exs. (Otherwise they used to follow folks back and have words
)