Abandoned Church or One-Room Schoolhouse.
This around the right hand side of the structure and is the actual front door.
There was nothing left of the floor here but the cross beams.
Two separate bathrooms, boys and girls.
Chalkboard on far wall.
We determined that it must have been either an abandoned church or school, as this was all that was left of the piano.
Back of structure with a giant hole in the yard.