St. Michael's Cathedral, Alba Iulia
Alba Iulia, Romania · built 1001
St. Michael's Cathedral (Romanian: Catedrala Sfântul Mihail, Hungarian: Gyulafehérvári Szent Mihály érseki székesegyház) is the cathedral of the Roman Catholic Archdiocese of Alba Iulia, Romania, and is the oldest and longest cathedral in the country.
Church data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).