Last Wall Standing!

Balquhain Castle was built in the 14th century by the Leslie family of Aberdeenshire. It was sacked in a feud with the other main local family of those times, the Forbes, in 1526. Rebuilt four years later, it housed Mary, Queen of Scots just before the battle of Corrichie, when her forces were defeated (standard practice?), and was finally burnt by Prince William, Duke of Cumberland ('Butcher Cumberland' or 'Sweet William', depending on your political viewpoint) after the Battle of Culloden, 1746.

Only two walls are left standing. The castle is protected as a 'scheduled monument'. Protected from what, one might ask? Another siege or simply the NE Scotland weather? Which wall will be the 'Last Man Standing'?