Tourism in the Republic of Ireland on were built by them. As Dublin Airport is located just outside the city, most international visitors to Ireland begin their stay here. Among the main attractions in Dublin are Dublin Castle, the seat of British rule in Ireland until 1922, Phoenix Park, one of the largest inner city parks in the world, The General Post Office, one of Ireland's most famous buildings due to the 1916 Easter rising, Kilmainham Gaol, a former prison turned museum that held and executed the rebels of the 1916 Rising and Trinity College, where the Book of Kells and the Book of Durrow are
Irish Citizen Army authorities tolerated the open drilling and bearing of arms by the ICA, thinking that to clamp down on the organisation would provoke further unrest. A small group of IRB conspirators within the Irish Volunteers movement had started planning a rising. Worried that Connolly would embark on premature military action with the ICA, they approached him and inducted him into the IRB's Supreme Council to co-ordinate their preparations for the armed rebellion which became known as the Easter Rising. On Monday, 24 April 1916, 220 members of the ICA (including 28 women) took part in the Easter Rising, alongside a much