The Archdiocese of Nueva Segovia is a Roman Catholic archdiocese located in the Philippines, specifically in the province of Ilocos Sur. Established in 1583, it is one of the oldest dioceses in the country. The archdiocese serves a diverse population and is responsible for the spiritual and administrative needs of its parishes. The archdiocese's seat is the Cathedral of the Immaculate Conception in the city of Vigan, a UNESCO World Heritage Site. It is part of the Ecclesiastical Province of Nueva Segovia, which includes several suffragan dioceses. The archdiocese plays a vital role in promoting the Catholic faith and community development in the region.