Revisiting the "pretty little marker pile site" in Princeton MA

I thought I would explore outward from the site I found the previous weekend. But it was a cloudy day and I kept going in circles. Luckily the circles brought me back to my car more than once, so by the time I knew I was lost I also knew where I was. But anyway this means I never did get very far from where I started and, I guess, I still have the exploring "outward" to do. My car was parked at the low point on Houghton Rd, where it crosses Wachusett Brook. I guess I can call this spot "in the shadow of Wachusett", as it is just south of the mountain. I have been exploring in there lately and this spot, north of the road, has some interesting stuff besides the first site I found.

So, I took another couple of photos of the marker pile site.The new fall colors are a pleasant change from the universally dark understory green of the summer woods.

I got as far as a hilltop, where I found possible fire circles and possible prayer seats, shown in previous post. Back at my car, I went a few yards east along the road and saw some other stuff in a wet spot just visible from the road to the north. Can you make this out?
It is a little bit of zig-zag stone line, ending in a messy pile under a tree. Other rocks in loose piles around the same low point suggest field clearing. But the zig-zag is carefully made. None of my pictures do much to show this feature.