Hello Tamara,
This was most likely a shepherds house, as the fields surrounding it are not suitable for crops, more for grazing. I would say it's too high up for cattle, so only sheep would graze here or maybe goats.
The stone left lying around is most likely worth a bob or two if anyone could be bothered going getting it.
It is a shame it has ended up like this, but the towns in this area have regenerated a lot in recent years, so there is a glimmer of hope for this building.
RE: RurEx - The Ramblings of an Old Man - Episode #1 - The House in the Wilderness