At the risk of copping out, I find it difficult to tell what's going on from the photo. Got any more from other angles?
Do the stones mebbe look a bit small or insubstantial for a tomb - what sort do you have in mind? (Or are they broken?) Are any/many of them 'erect'* (as in stuck upright in the ground*) & if so do those make any sense as part of a tomb?
*I can't think of the right word!
Not sure what else it looks like - other than the possibility of clearance.
love
Moth