Elevation Markers on Round Top Hill, highest peak in Hampden County

From Wikipedia, the free encyclopedia

Survey markers, also called survey markssurvey monumentssurvey benchmarks or geodetic marks, are objects placed to mark key survey points on the Earth’s surface. They are used in geodetic and land surveying. Informally, such marks are referred to as benchmarks,[1] although strictly speaking the term “benchmark” is reserved for marks that indicate elevation. Horizontal position markers used for triangulation are also known as triangulation stations.