In reply to alan.rodger:
I'd guess you're referring to The Drey. It was built by the Edinburgh Squirrels (hence the name). I was in it about 4 years ago, I picked up a hitcher who was one of a small group who spend their time there doing it up so I dropped in for a nosey when I dropped him off. I don't know the exact dates of its original build or how much it was used. There used to be quite a few dosses in the glen, less now.