What the heck - interesting potentials here. So, I'll take some time now to belabour you with some few of my thoughts:
For there to be any collective and/or social memory of the place and the events we are looking at the violation of major Taboo structures on all sides.
Not just mass killing and refusal of burial.
The events which led up to the mass killing and stimulated the resident group to kill must have been quite a series of major violations in themselves.
These people (victims?) were not taken and subjected to judgement, etc. But were killed and left to rot. "Ground sowed with salt" type of thing.
Seems nothing was ever done with the ground itself...in an area of limited soil/tillable land?? Hmmm. Seems that even the ground was considered un-clean/un-safe and to be left fallow. "Who knows what might grow from such ground?"
Leaving the bodies to rot would have been un-pleasant for those who lived near/around the site. Major Taboos would have to be over come by the violation of greater Taboos and for this taint to remain for over a thousand years??
I am unaware of any claims of 'psychic' activity for this site but have not investigated the anecdotal material, if any. Usually there is some and may not be freely/openly spoken of.
If the site is still, 2014, considered to be un-safe...this would tend to indicate that some major collective trauma is still referenced within this community, at least.
Love to know more about it and the events surrounding the mass killing. History is such a delightfully revealing place. Humans do leave such marvelous trace evidences of their passage.