Just another of those little things

There are hills lying along the north of the Assabet River where Rt 495 meets Rt 290. I realized these might be worth exploring as I passed on my way to Northborough and, since I did not have such a succesful exploration of there, I stopped on my way back, parked behind a company and went up one hill looking over the river to the south and to Rt 495 to the east. Here we are on a southward facing shoulder:It is easy to guess this is a fire ring and a comfortable little place to sit in front of a fire. But up on the shoulder of a hill like this? I don't see any charring on the inner surface of the rocks in the circle. One of these days I am going to have to take a picture of a fire ring so we can compare with something like this - just one of those suspicious little things you find out in the woods.

Imagine for a moment that this is not a fire place. Then what is the bench for?