"Lost in the Trees"
I promised not to tell where this is exactly but I will say that it's very difficult to get to and very dangerous so don't go there! There's ghosts in the woods!
"Natural Hot springs"
There are hot springs all over Japan, this is a natural lake...we didn't go in, we went to the civilized onsen just down the road, no need to get naked and post hole through the snow and ruin this nice scene...