text: I had another look and you are also right. From Craigour Drive there is a track but people then fan out over the grass so it's very hard to see from Upper Craigour. 
  But at Craigour Drive there is a 2m high steel fence, somebody pulled out some of the vertical bars and you actually have to climb through the hole in the fence and step over the horizontal bottom bar. I see if the OSM wiki gives any insight how to tag this. 
  
  
  