The Office of Bishop in Nitra is administrator of Nitra Castle, one of the most significant monuments in Slovakia. It was built on a limestone rock, which is surrounded by the meander of the Nitra River from three sides. The Castle of Nitra is a cultural heritage and together with the Upper Town on the southern slope of the castle hill was proclaimed a Town Conservation Reserve. The Castle of Nitra consists of four independent parts: the cathedral, bishop palace, outbuildings and outer walls with one entrance gate.