He asked me to not say where these are from. The pictures include some interesting small structures.
This is a standing stone , grown into a tree, with a small piece of quartz-like material on the ground a foot in front of it. Given how the quartz is placed with relation to the leaves, it looks like it must have been placed there not too long ago.
This looks to be two examples of short linear arrangements of rocks ending in a small triangular standing stone.Some supported piles with a small number of upper rocks: