Sounds like you are describing "Hand-Holes" for access / verification of the Clamps and GEC at the rod(s).
Is this correct???
Seen a couple places which had redundant ground rods for supplimental electrodes, and they were driven outside of the gear room (and ended up in the finished sidewalk - resulting in round "Hand-Holes").
These had covers with the phrase:
"Ground Rod", "Grounding Electrode" (or something similar) imbossed on them.
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!