In the background, on the right, is the Wallace Monument on the Abbey Craig.
For more about the stone, and for more context, see
Image, which I took on the same occasion.
For other views, see
Image /
Image (with useful links) /
Image
The inscription on the plaque is as follows: "The Beheading Stone: Protected by the public at the instance of the Stirling Natural History & Archaeological Society / 1887".
The stone, long before it was enclosed in the present structure (which is the work of John Allan), was mentioned by William Nimmo in his 1777 "History of Stirlingshire". I cannot vouch for his historical accuracy, but merely quote the relevant passages below for interest.
From page 252: "Opposite to the castle, upon the north, lies the Gowan Hill, upon which is a stone, with an inscription, but it is unintelligible, nor does it appear, from the form of the letters, to be of any great antiquity. Upon the northern extremity of this hill, near the bridge, is a small mount, well known in the neighbourhood by the uncouth name of Hurly-Haaky, surrounded at the top with a parapet of earth, and having other remains of artificial works upon it. Upon this mount, Duncan Earl of Lennox, with his son-in-law, Murdoch Duke of Albany, who had been sometime governor of the realm, was beheaded, May 18th 1425, as were Walter and Alexander Stewarts, sons of that Duke, the day following".
On page 255 of the same work, Nimmo mentions this location again, stating that "it is highly probable, that Hurly Haaky was the mote hill of the castle of Stirling, or perhaps of a much larger jurisdiction".
For the meaning of "mote hill" (or "moot hill"), compare
Image,
Image, and the final few paragraphs at
Image
The name "Gowan Hills" was formerly applied to what is now Gowan Hill, Mote Hill, and the part that was later reshaped to form Ballengeich Cemetery. That earlier usage is reflected in the quotation from p252 of Nimmo, above.