For anyone who has any experience at Gretchen's Lock, you will recognize this as the old house that once graced the park. I would call your attention, however, to the slab of stone in the far right pic that lies closest to the road. On that slab of stone was the circle carving above. I often wondered what that might be. One possibility is called a Rune, an ancient symbol or form of writing. They first appeared some 1500 years ago in Europe. As Christianity took hold, the runic alphabet became reviled as a pagan practice, and eventually was little seen. The word "rune" comes from an Anglo Saxon word meaning secret or mystery.
It was also used by the Vikings. As near as I can guess, this symbol on the stone above could mean comfort, joy, or glory on one hand (WUNJO, W). But if it is a different letter (URUZ, U), then it could mean strength, speed, or good health. All are positive things.
I have also considered the possibility that it might be Native American, though from what I have seen, those symbols are far more complicated.
Sadly, there is no way to study it. I think they pushed it into the well along with the rest of the house. I didn't know anything about Runes at the time, or maybe I could have told someone and it might have been saved. As it is, I at least have the pics I took of it. If you know what this might be, if anything, please email me or leave a comment!