The King's Knot, a geometrical earthwork in the former royal gardens below Stirling Castle, has been shrouded in mystery for hundreds of years.
Though the Knot as it appears today dates from the 1620s, its flat-topped central mound is thought to be much older.
Writers going back more than six centuries have linked the landmark to the legend of King Arthur.
Archaeologists from Glasgow University, working with the Stirling Local History Society and Stirling Field and Archaeological Society, conducted the first ever non-invasive survey of the site in May and June in a bid to uncover some of its secrets.
Their findings were show there was indeed a round feature on the site that pre-dates the visible earthworks.