From A Weird Welshie Neolithic Loving Human, these are fastinating to me. I've never seen this site before nor can I recall ever seeing images of it.
In Wales we have a lot of Neolithic Structures however non are quite like that. It's very impressive.
Looking from the Alignment of the stones and the gauges cut into them I also came to a similar conclusion and though't they would contain wooden planks or branches and be used as early agricultural fencing.
Using Skara Brae as an example that is a very early neolithic site which is square/rectangular which if I am correct in thinking would usually be associated much later with the Iron Age.
However with the stones dated at 6000-7000 years ago that would fit a theory based on the turn of the agricultural revolution at the same time period.
With regards to the Lego like stones, I find this really interesting. As a building concept it seems almost obvious in a weird way but from a tool perspective what could cut into something like that? Or, alternatively was it chiseled out over time slowly?
Fantastic post, I've enjoyed the thought process = D