A couple of years ago my 'better half' had a similar experience at West Kennet Long Barrow. While myself and Dafydd happily wandered about inside she took one step inside and literally ran out. She said she 'sensed' the spirts of people and that we shouldn't be in there. Karen is sensitive to such things although it has never happened to me.
We have visited many burial chambers over the years and rarely will she step inside one due to the 'feelings' she gets. The few she has is because she says there is nothing to 'sense' at those sites.

More recently, on Orkney, I was in Minehowe with Dafydd and he was very uneasy and wanted to get out asap. Dafydd has been in many burial chambers etc and has never been like this before (or since). This was the site Tony Robinson with Time Team couldn't wait to get out of. Although I was not like that there was certainly something 'different' about the atmosphere inside Minehowe.