There is something about rock walls that is special. Maybe it is imagining the labour of having to place each of them so skillfully they would stand and not fall. Maybe it is how they stand like a sign of the past, defiantly weathering the elements to remain. Maybe it is just the reminder lessons learned marked by an old foundation that is nothing more.
I think photography and #wednesdaywalk is like a superpower for being active, living in the moment and connecting with others. Some of the most important things in life.
I think the something about rock walls could well be all the things you said :)