Have you ever seen this marker? This is a US. Coast & Geodetic Survey Bench Mark from 1934. This is just 1 of 17 (!!) located in Turner County.

There is a 44 page doc you can read ALL about this! These reference points are developed and maintained by NOAA’s National Geodetic Survey (NGS). These permanent marks are called “survey marks” (you may hear survey marks called “benchmarks,” but benchmarks are only one type of survey mark). Often, survey marks are marked with a metal disk like the photo below, set in concrete or bedrock:

https://www.ngs.noaa.gov/web/about_ngs/history/Survey_Mark_Art.pdf

If you want to try to find them, you can search this interactive map for the locations of all 17!

https://noaa.maps.arcgis.com/apps/webappviewer/index.html?id=190385f9aadb4cf1b0dd8759893032db

Location: Corner of E. College Avenue & McLendon St. in Ashburn, GA
Date: February 20, 2021