Not sure what this is. Me and my friends speculate it is a main cabin for possibly an old camp ground of some kind. It has what we think are two bathrooms, an indoor & outdoor fire pit, a gravity waterfall, and then a main room area up some stairs. It's not very big. But the area outside, there are no cabins nearby. Maybe tent camping site? But there is a house next door (the owner) and that house is definitely newer than this building so I am not sure. Why leave this building up but tear everything else down if there was something?
Anyways, while wandering around on their property to get back to my car, I found some remnants of either old foundation, or an old dam. A half-assed treehouse. And a random house with some weird insulation in it. It's also pretty slanted and about to fall off it's foundation. Album for your viewing:
https://flic.kr/s/aHsmMz3tmZ IMG_6633 by
UE_Kote, on Flickr
IMG_6640 by
UE_Kote, on Flickr
IMG_6650 by
UE_Kote, on Flickr
IMG_6656 by
UE_Kote, on Flickr