The address is 19 Main Street - we took a left at that oddball intersection onto Main, and it's around the corner on the right hand side, right on the water. It's a pretty old brick building, they have a bar downstairs which I would bet has a gorgeous view, too, just didn't take the kids downstairs to find out. The war memorial is immediately on the right when you take the left onto Main St, right? It's down the street a bit from there, on the same side.
I'm not sure how long she's been open, I know it's been months that I've been trying to get up there (and I'm glad we finally did!)