Came across it while on a footpath in Snowdonia, North Wales. Plenty of Iron Age hut circles and homesteads in the area but found this to be a very unfamiliar shape!
[Photograph] (https://imgur.com/gallery/AfffH)
[Google Maps location] (http://maps.google.com/?q=53.220742,-3.975777&hl=en&gl=gb)
The very irregular walls and sprawling arrangement of the spaces makes it hard to imagine any kind of roof or system of roofs. If you discount the possible roofing of the space, it begins to look much more like an enclosure for sheep, like these. At least, in part. The middle of it looks like it might have once been a site for a hut.