Southern Dobruja (Bulgarian: Южна Добруджа, Yuzhna Dobrudzha or simply Добруджа, Dobrudzha) is an area of north-eastern Bulgaria comprising the administrative districts named for its two principal cities of Dobrich and Silistra. It has an area of 7,565 km² and a population of 358,000. When it was a part of Romania from 1913 to 1940 it was known in  Romanian as Dobrogea de sud, the Cadrilater ("Quadrilateral"), or Dobrogea Nouă ("New Dobruja").