SUNDAY'S "meet the experts" day at Nottingham Castle unearthed another unique Nottingham Great War artefact.
Michael Walker of Watnall took along a carefully embroidered khaki handkerchief that was given to his grandfather Albert Walker.
Albert, pictured, served as a corporal with the 2/8th Sherwood Foresters and was awarded two gallantry awards exactly one year apart , both involving the use of Mills bombs.
On April 27, 1916, he bombed rebels in a room-to-room fight in a nurses' home during the Dublin Easter Rebellion.
And on April 27, 1917, he threw bombs to repel a German attack during the Battle of Arras on the Western Front.
The Distinguished Conduct Medal and bar that he received for these two actions is in the Sherwood Foresters Museum on the ground floor of Nottingham Castle.
The handkerchief was given to him by his brother Garnett Walker
Carefully embroidered on to it in great detail is a map of the trenches occupied at some time by the Sherwood Foresters.
The map includes representations of the Foresters' trenches, neighbouring trenches held by the North Staffords, belts of barbed wire, communications trenches, shell holes, a light railway, artillery positions and a wood and a village with church.
The panel of experts at the castle – John Cotterill, Tim Chamberlin, Richard Clay and Mel Siddons – had never seen anything like it.
They are now going to pore over volumes of trench maps to discover whereabouts the Foresters trenches portrayed on the handkerchief actually were and what their significance was to gallant bomber Albert Walker.