Question: What was the location of the execution of Roger David Casement, the Irish Nationalist who made made efforts during World War I to gain German military aid for the 1916 Easter Rising that sought to gain Irish independence?

Passages:
Roger David Casement (1 September 1864 – 3 August 1916), formerly known as Sir Roger Casement  between 1911 and shortly before his execution for treason, when he was stripped of his knighthood and other honours, was a British civil servant who worked for the British Foreign Office as a diplomat, and later became a humanitarian activist, Irish nationalist, and poet.  Described as the "father of twentieth-century human rights investigations", he was honoured in 1905 for the Casement Report on the Congo and knighted in 1911 for his important investigations of human rights abuses in Peru.  He then made efforts during World War I to gain German military aid for the 1916 Easter Rising that sought to gain Irish independence. <P2-S0> Sir Roger Casement is a 1968 German television miniseries depicting the efforts of the historical figure Sir Roger Casement to seek German aid for Irish independence during the First World War and his attempts to form an Irish Brigade of Prisoners of War. <P2-S1>  It was aired in two 90 minute parts. Mary Josephine Ryan (29 December 1884 – 16 April 1977) was an Irish nationalist.  She was a member of Cumann na mBan and the honorary secretary of the executive committee.  She took part in 1916 Easter Rising and War of Independence. Marcella Cosgrave (30 April 1873 – 31 January 1938) was an Irish nationalist.  She was a founder member of Inghinidhe na hÉireann and Cumann na mBan and took part in the 1916 Easter Rising and Irish War of Independence. Liam Mac an Ultaigh of Dublin (fl.  c. 1965) is an Irish Nationalist and was Chief Scout of the Fianna Éireann from 1965.  In such tenure, Mac an Ultaigh is most recognized for his work on the Committee that under his administration drafted the Fianna Handbook’s 3rd or 1965 (1st 1913, 2nd 1924) edition, which uniquely of the editions attempts to chronicle the organization’s history.  Notably, this thorough and well documented Handbook history conclusively disputes traditional histories, which credit the Irish Republican Brotherhood’s Bulmer Hobson with founding the “Scouts” and exposes a, possible, anti-feminist bias in the traditional histories.  The 3rd Handbook in its section “The History and Tradition of the Fianna Éireann” at its pages 24–26 credits instead the Sinn Féin’s Constance Markievicz or “the Countess Markievicz” with founding “Na Fianna Éireann”.  As already noted in the Wikipedia article Fianna Éireann, Patrick Pearse has stated that the creation of Fianna Éireann was historically as important to the liberation of Southern and Western Ireland from British rule and the founding of the Irish Free State and, later, the Republic of Ireland as was the creation of the Irish Volunteers in 1913.  The paramilitary Fianna Éireann youth Scouts were involved particularly with gun running commencing with the 1916 Easter Rising and later in combat, particularly in Dublin, during the Civil War period of 1922-1924. Patrick Belton (1884 – 30 January 1945) was an Irish nationalist, politician, farmer, and businessman.  He was strongly anti-communist and he was a founder and leader of the Irish Christian Front.  Closely associated with Michael Collins, he was active in the 1916 Easter Rising and in the Republican movement in the years that followed.  Belton later provided a strong Catholic voice in an Irish nationalist context throughout his career.  Supportive of General Francisco Franco, Belton however opposed General Eoin O'Duffy taking an Irish Brigade to Spain, feeling that they would be needed in Ireland to counter domestic "political ills".  His family, including three sons and a granddaughter (Avril Doyle), also went on to have careers in Irish politics. <P1-S0> The "Irish Brigade" was an attempt by Sir Roger Casement to form an Irish nationalist military unit during World War I among Irishmen who had served in the British Army and had become prisoners of war (POWs) in Germany. <P1-S1>  Casement sought to send a well-equipped and well-organized Irish unit to Ireland, to fight against Britain, in the aim of achieving independence for Ireland. <P1-S2>  Such an action was to be concurrent with the ongoing war between Britain and Germany, thereby providing indirect aid to the German cause, without the ex-POWs fighting in the Imperial Germany Army itself. Michael Thomas Christopher Mallin (Irish: "Micheál Ó Mealláin" ; 1 December 1874 – 8 May 1916) was an Irish rebel and socialist who took an active role in the 1916 Easter Rising.  He was a silk weaver and co-founder with Francis Sheehy-Skeffington of the Irish Socialist Party, was second in command of the Irish Citizen Army under James Connolly in the Easter Rising of 1916 and commanded the garrison at St. Stephen's Green in Dublin, with Kit Poole as his second in command. Rahoneen ("Ráth Eoghainín") is a townland of Ardfert in County Kerry, Ireland.  It is notable as the location of an ancient Celtic ringfort; at one time this was known as McKenna's fort, but, after the capture and execution of Roger Casement for treason, sabotage and espionage against the Crown, it became known as Casement's Fort.  In the early hours of 21 April 1916, Casement was put ashore at nearby Banna strand from "U19. "Too weak to travel, he was discovered at McKenna's Fort where he had hidden after arranging delivery of German weapons as part of a plan of arming Irish rebels and creating a rising in 1916 against the British to achieve independence. Na Fianna Éireann (The Fianna of Ireland), known as the Fianna, is an Irish nationalist youth organisation founded by Bulmer Hobson and Constance Markievicz in 1909.  Fianna members were involved in the setting up of the armed nationalist body the Irish Volunteers, and had their own circle of the Irish Republican Brotherhood (IRB).  They took part in the 1914 Howth gun-running and (as Volunteer members) in the 1916 Easter Rising.  They were active in the War of Independence and took the anti-Treaty side in the Civil War.

Supporting sentences:
"Too weak to travel, he was discovered at McKenna's Fort where he had hidden after arranging delivery of German weapons as part of a plan of arming Irish rebels and creating a rising in 1916 against the British to achieve independence.  Described as the "father of twentieth-century human rights investigations", he was honoured in 1905 for the Casement Report on the Congo and knighted in 1911 for his important investigations of human rights abuses in Peru.