Hub
From PLANTFACTS.OSU.EDU
1. A 2" x 2" stake used by surveyors.

The surveyor hub on the right has an identification tag.
Source: http://www.metrokc.gov/kcdot/roads/eng/survey/monuments.cfm
1. A 2" x 2" stake used by surveyors.

The surveyor hub on the right has an identification tag.
Source: http://www.metrokc.gov/kcdot/roads/eng/survey/monuments.cfm