This region is divided in three smaller regions : Oberfranken , Mittelfranken , and Unterfranken . The biggest city in Franconia is Nuremberg . The Bavarian part is made up of the administrative regions of Lower Franconia ( Unterfranken , capital city WÃ 1\/4 rzburg ) , Middle Franconia ( Mittelfranken , capital city Ansbach ) , and Upper Franconia ( Oberfranken , capital city Bayreuth ) .