The Eleventh Night is observed in Northern Ireland every July 11, the night before Orangemen's Day or the Twelfth. This celebration is linked to the Glorious Revolution and the Williamite War, specifically the Battle of Boyne, which solidified Protestant dominance in Ireland. Many Protestant unionists and loyalists, along with the Orange Order, commemorate this night by lighting large bonfires in Protestant neighborhoods across Ulster, some exceeding 100 feet in height. However, the event can also lead to tensions between Protestant and Catholic communities, as some individuals use the occasion to display hostility towards Irish Catholics by burning symbols of Irish republicanism and nationalism on the bonfires. Such actions are widely condemned for inciting sectarian hatred. Additionally, the bonfires pose environmental and health concerns, particularly when tires are burned, releasing toxic chemicals.