In land surveying, what do we call the special, durable installations—often of stone or concrete—that permanently mark the exact locations of control points determined by precise survey work? Select the standard term for these permanent reference points.

Introduction / Context:
Boundary and control points must be recoverable years after a survey. To ensure permanence and legal reliability, surveyors set durable physical markers at key coordinates. Knowing the correct terminology for these installations is essential for interpreting plats and conducting resurvey work.

Given Data / Assumptions:

• The installation is durable (stone, concrete, metal) and intended to be permanent.
• It marks a precisely determined location used for property or control.
• We require the standard surveying term for such markers.

Concept / Approach:

Survey monuments are permanent markers that identify specific survey points—corners, benchmarks, or control stations. They may include caps with identification, elevations, or coordinate data. Their permanence supports legal boundary retracement and geodetic control.

Step-by-Step Solution:

Verification / Alternative check:

Standards and statutes in many jurisdictions define how monuments are set, described, and documented to maintain the cadastre and geodetic networks.

Why Other Options Are Wrong:

Topographic marks: not a standard term; topographic mapping uses benchmarks and spot elevations, but the generic “marks” is imprecise.

Hatchures: refers to drawing shading lines, not survey markers.

Pillars: a physical structure type, but not the surveying term; some geodetic stations use pillars, yet the correct generic term remains “monument.”

Common Pitfalls:

Assuming any stake is a monument. Temporary stakes guide construction but lack the permanence and legal status of a monument.

Final Answer:

Monuments