A lot of people who cleared fields back in the late 1800 and early 1900's would stick rocks like that (in a pile) to clear their fields for plowing.
But that looks like a grave to me LMAO.
BTW I made that shit up Kissy Face.
LOL i have several different ones anyways and this one is the easiest to replace if i ever get the itch.
But still unsure just looking at different angles.