Neighbor's concrete supports on our property

There are so many things that are commercially purchased ridiculously expensive, but if you know someone, or get creative ... we have sandstone in the ground, especially the houses with basements have dug up some pretty big chunks. Of course, they all have them hauled away expensively, even though you could use them to design the garden, for example. Nobody does that anymore in times of grey welded wire fences and robotic lawn mowers. Unfortunately.

There are so many things that are ridiculously expensive when bought commercially, but if you know someone, or get creative... we have sandstone in the ground, especially the houses with basements have dug out some pretty big chunks. Of course, everyone lets them be hauled away expensively, even though you could use them, for example, to design the garden. Nobody does that nowadays with gray wire fencing and robotic lawn mowers. Unfortunately. Nobody is interested in natural stone walls and the like. In the village, you also ask the farmer if he can haul something for you, etc., the city dweller hires companies with fleets, and that adds another zero to the price.

what distinguishes a Friesenwall compared to other dry stone walls? That it consists of pebbles (i.e. rounder stones) or what?