General Post Office, Dublin

This grand building on O'Connell Street is both a working post office and a national monument central to modern Irish history. Completed in 1818 with a portico of six Ionic columns, it became the headquarters of the rebels during the 1916 Easter Rising, when the Proclamation of the Republic was read from its steps. The fighting left the building gutted, and the bullet marks on its columns are still visible. A museum inside, GPO Witness History, recounts the events of the rising and their aftermath.