It was the site of V Beach, the landing zone for two Irish battalions, including one from the SS River Clyde, on 25 April 1915 during the Gallipoli Campaign in World War I.
The castle was bombarded by the Royal Navy on 3 November 1914, causing serious damage and killing 86 Ottoman soldiers.
Sedd el Bahr was subjected to repeated bombardment and raids by naval demolition teams and the position was deemed too exposed.
By the peak of naval operations on 18 March, Sedd el Bahr and Kum Kale, across the straits, had been eliminated as threats.
This line references the 1916 Easter Rising, which took place in Ireland around a year after the landing at Suvla Bay as part of the Gallipoli Campaign.