A view of the "Casemates" barracks, behind the defensive wall from which it derives its name. The wall cuts the North Yard, and the northern tip of Ireland Island off from the area to the south, and was meant as almost the last point of defence against an overland attack on the HM Dockyard Bermuda (the last line of defence was at the Keep, at the very northern extremity of Ireland Island). After the closure of the dockyard, the Casemates barracks was used for a time as a prison, hence the addition of watch positions on its upper corners.