A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Ronald van Riet
Date: 2018 Sep 23, 01:33 -0700
Benchmarks such as these are present in many countries, including the USA and The Netherlands. In both cases, these are small markers (in The Netherlands like large nail heads or the top of a church tower) which should give a better accuracy than the 6-inch or so (?) stone marker used in your example.
Many of the US benchmarks can be viewed on http://www.waymarking.com/wm/search.aspx?f=1&kw=benchmarks&st=2 whereas many of the Dutch benchmarks can be viewed on http://www.waymarking.com/cat/details.aspx?f=1&guid=d905f699-65da-41c8-84d0-354e1ab33833&st=2. A good example of the nail-type of Dutch benchmark is http://www.waymarking.com/waymarks/WMWWN0_RD_Meetpunt_279327_Vaassen.