Yes, I too have peered over the wall, but could only see some boggy land, that's why I was aksing if there was ever a well structure in place.
BTW Martin, its a long shot, but you aren't the guy that jogs at 630am in the morning through the park, who stopped me as I cycled past to ask about folklore (for no apparant reason as far as I could tell, I dont do the whole tartan look going to my job as a guide, so I figured he was just someone passionate about the park who accidentally "hit the jackppot" in stopping me, as he said).
6.30am?? Jogging?? haha- no, most definately not me!!! I live down the Borders now (but still work in Edinburgh)... Rather strange doncha think that a random stranger stops to ask about folklore at 6.30am??!!!
Cheers,
Martin