Near Silver Lake, Hollis NH - with my son Joe

I took a wonderful walk with my son to the northwest of Silver Lake Park in Hollis NH. We hopped the chain link fence (above the "E" in "SILVER" on the map), saw one small rock pile, then continued up and on. Joe asked about the names of plants and, it turns out, I know some of them. We just headed up that ravine leading to 'A' where there were some uninteresting, well buried, ground piles. Only noteworthy in that they occur at the very top of the water course which leads from there downhill into...a "Beaver Brook" and the Nittinisset River. Here is one:

From there our uphill progress were blocked by houses and we popped out to the road (Federal Hill Rd). At 'B' there was a sequence of low knolls overlooking the wetland. Each one had the remnants of some kind of mound on top. This is noteworthy, mainly because I found others like them the following weekend over in Gardner. Noteworthy but not particularly pretty. Pictures are below.

Finally we got out to the road, went further north and followed a town trail west, past a wetland and up under the power lines. As soon as we could we ducked back into the shadows under the trees and found something interesting at 'C' - unique and pretty. Let's start with pictures of this. First you see a big boulder with a curved rock pile in the foreground:

Then you notice a bit of wall coming out from the boulder. And notice it ends with a collapsed niche:

closer

Further poking around, finds two more short sections of "wall": one connected to the uphill side of the boulder:

And another, a few feet away uphill:

So what is this collection of boulder, short walls, niches, curved pile? Joe took these pictures with his iPhone:

From these, it seems clear (and we agreed at the time) that this is an old trail that divides and goes on either side of the boulder. I don't know what that extra bit of wall is for but I do believe this is a "sacred pathway" rock pile site. It is designed to guide someone in a formalized passage. The presence of a niche is consistent with this. That was the high point of our walk - I had chosen to step into the woods at exactly this spot, so our  steps were actually following the old pathway. You can see the light under the power lines in the background of this last picture - we came straight here.

Let's take a look at the "mounds" at 'B'. They do not photo well, especially in bright sunlight; and they are messy and formless anyway. For example:

Here is another:

and another:

I want to call attention to these - messy mounds, with internal structure, on knolls, adjacent and overlooking headwaters. Probably pretty old.
There were other things to see, for example, around 'D':

It was such a pleasure to be out with a son. Also I got to make my point, which was that there are rock piles pretty much everywhere you go in the undisturbed woods.