Where in Duluth?

I'll guess in the woods above Norton Park and below Spirit Mountain. I think that area is called Cramer's Addition.

Nope.

Lester Park.  It's on the narrow strip of woods between the river and Lester River Road, just past the golf course clubhouse. I've always wondered about its history.

That is correct.

I'll stump you yet, Birdsandboards.

I look forward to being stumped. That means there's something cool out there that I haven't stumbled across yet. There's no shortage of ruins and hidden away nooks around here.  I was hoping Paul would chime in with some history on that old hearth.

I have no clue. I blame Lester, whoever Lester was.