I have recently joined this group: http://www.bench-marks.org.uk/ who are devoted to spotting and recording bench marks in the UK.
Bench marks were used by the Ordnance Survey surveyors to record a specific altitude above sea level, when making maps. The marks have fallen into disuse with the advent of aerial and GPS surveying methods. They are little records of the cartographers from many years ago.
There are probably similar marks all over the world, where maps were made by manual measurements. There may be similar groups who engage in similar activities elsewhere in the world.
(also a member of the Cloud Appreciation Society)
Wow Tony . . . fascinating indeed . . . we see postcodes can be typed in and then a list pops up listing bench marks in the code’s area . . . that’s almost too exciting for us to watch.
Those are two find appreciation societies you belong to. Congratulations.