We are barely aware of them in our daily life, but stones, bolts and various other markers are put in place by surveyors in fields, on roadsides and on buildings. A distinction is made here between two types of points:

Fixed points

The term «fixed point» refers to a point permanently indicated on site with a granite stone or bolt – in some cases protected by a shaft. In the case of fixed location points, the coordinates (and usually the height) are calculated with a high degree of accuracy, while for fixed height points the height is calculated to within the millimetre range.
These fixed points are used for surveying other objects such as border points, corners of buildings, edges of roads, etc.
Fixed points thus define the spatial reference and form the basis for maps, plans and geographic data.

Border points

Border points indicate the course of borders and boundaries. The connections between neighbouring points form the actual border or boundary. Here a distinction is made between national, cantonal and municipal borders, and boundaries of plots of land. 
Border points are indicated on site with the aid of markers, which may take the form of granite stones, brass bolts, pipes, plastic markers or crosses engraved in stone. National, cantonal and municipal borders are usually indicated in a decorative manner, and often include dates and coats of arms.