The front stairs at Spencer (above) come into view once the barricade of the front gate has been overcome. There are six doorbells mounted on that gate (below) but only some of them work and only some of the time.
This is all a hundred years old or so, there isn't anybody around who actually knows anything about the house's history, but it seems pretty certain the San Francisco building codes would no longer permit features like these exiguous triangular treads in their tight descending spiral.