The Citadel is a fortress atop Gellért Hill. It was constructed by the Habsburg Empire in 1854, following the suppression of the Hungarian Revolution of 1848. The Citadel offers a beautiful view of the city, including the Buda Castle, the Parliament, the bridges over the Danube, all of Pest, and the Buda Hills. No wonder in 1987, the UNESCO named Gellért Hill a World Heritage site, together with Castle Hill and the panorama of both banks of the Danube. The Citadel and its Liberation Monument have become icons of Budapest.