A permanent structure used to mark the position of a surveyed point. Common locations for monuments include property or PLSS corners, vertical control points (benchmarks) and horizontal control points (sometimes called triangulation stations).
A physical structure, such as an iron post, marked stone, or tree in place, which marks the location of a corner point established by a Cadastral Survey. Objects, to be ranked as monuments, should have certain physical properties such as visibility, durability and stability, and they must define location with out resorting to measurements. "Monument" and "corner" are not synonymous, although the two terms are often used largely in the same sense.