Buchaam is on the A97 south west of Glenkindie but befor the croosing of the Don. Head up the signposted track and go to the farmhouse to ask permission. This souterrain is in the garden.
Mr Ogg who runs the farm took time out from doing paperwork to give a history lesson. In 1895 the house was extended at both ends which led to the souterrain being terribly damaged. However they repaired it as best they could. In later years he asked permission to block the entrance as his children would have been endangered. The end nearest the house he covered until the children were well into their teens. I'll stick up the Canmore notes which gives a fuller account.
To get into the souterrain is simple enough if you fancy crawling in on your stomach. Still, an excellent start to the day.