Provinces of Bulgaria in the context of "Kardzhali Province"

Southern Dobruja or South Dobruja (Bulgarian: Южна Добруджа, romanized: Yuzhna Dobrudzha or simply Добруджа, Dobrudzha; Romanian: Dobrogea de Sud or Dobrogea Nouă, lit. 'New Dobruja'), also the Quadrilateral (Romanian: Cadrilater), is an area of north-eastern Bulgaria comprising Dobrich and Silistra provinces, part of the historical region of Dobruja. It has an area of 7,412 square km and a population of 358,000.

It is historically noteworthy as a point of contention in Bulgarian-Romanian relations. Part of Bulgaria between 1878 and 1913, the region was annexed by Romania in the Treaty of Bucharest (1913), targeted by Bulgaria during World War I (1914–18), and subsequently remained Romanian until 1940, when Bulgaria regained control in the Treaty of Craiova, which went along with a compulsory population exchange. Southern Dobruja has been part of Bulgaria since 1940.

42°15′N 23°0′E / 42.250°N 23.000°E / 42.250; 23.000

Kyustendil Province (Bulgarian: Област Кюстендил, romanized: Oblast Kyustendil) is a province in southwestern Bulgaria, extending over an area of 3,084.3 km (1,190.9 sq mi) (constituting 2.7% of the total territory of the Republic of Bulgaria), and with a population of 106 131. It borders the provinces of Sofia, Pernik, and Blagoevgrad; to the west, its limits coincide with the state borders between Bulgaria and North Macedonia, and between Bulgaria and the Republic of Serbia. The administrative center of the Province is Kyustendil.

42°40′N 23°40′E / 42.667°N 23.667°E / 42.667; 23.667

Sofia Province (Bulgarian: Софийска област, romanized: Sofiyska oblast) is a province (oblast) of Bulgaria. The province does not include Sofia in its territories, but Sofia remains the seat of its administration. The province borders on the provinces of Pernik, Kyustendil, Blagoevgrad, Pazardzhik, Plovdiv, Lovech, Vratsa, Montana, and "Sofia City Province" (which is in a separate oblast, see Sofia Administration), and borders with Serbia to the northwest.

41°40′N 24°35′E / 41.667°N 24.583°E / 41.667; 24.583

Smolyan Province (Bulgarian: Област Смолян, Oblast Smolyan; former name Smolyan okrug) is a province in Southern-central Bulgaria, located in the Rhodope Mountains, neighbouring Greece to the south. It is named after its administrative and industrial centre — the city of Smolyan. The province embraces a territory of 3,192.8 km (1,232.7 sq mi). that is divided into 10 municipalities with a total population of 124,795, as of December 2009.

41°50′N 25°55′E / 41.833°N 25.917°E / 41.833; 25.917

Haskovo Province (Bulgarian: Област Хасково, romanized: Oblast Haskovo; former name Haskovo okrug) is a province in southern Bulgaria, neighbouring Greece and Turkey to the southeast, comprising parts of the Thracian valley along the river Maritsa. It is named after its administrative and industrial centre: the city of Haskovo. The province has a territory of 5,533.3 km (2,136.4 sq mi) that is divided into 11 municipalities with a total population, as of December 2009, of 256,408 inhabitants.

43°48′N 22°41′E / 43.800°N 22.683°E / 43.800; 22.683

Vidin Province (Bulgarian: Област Видин) is the northwesternmost province of Bulgaria. It borders Serbia to the west and Romania to the northeast, and its administrative centre is the city of Vidin on the Danube river. The area is divided into 11 municipalities. As of 2023, the province had a population of 72,754.

Lovech Province (Bulgarian: Област Ловеч, romanized: Oblast Lovech, former name Lovech okrug) is one of the 28 provinces of Bulgaria, lying at the northern centre of the country. It is named after its main city: Lovech. As of December 2009, the population of the area was151,153. It covers a total area of approximately 4,129 square km and includes 8 municipalities.

43°25′N 24°40′E / 43.417°N 24.667°E / 43.417; 24.667

Pleven Province (Bulgarian: Област Плевен or Плевенска Област) is a province located in central northern Bulgaria, bordering the Danube river, Romania and the Bulgarian provinces of Vratsa, Veliko Tarnovo and Lovech. It is divided into 11 subdivisions, called municipalities, that embrace a territory of 4,653.32 km (1,796.66 sq mi) with a population, as of February 2011, of 269 752 inhabitants. The province's capital is the city of Pleven.

43°19′N 25°33′E / 43.317°N 25.550°E / 43.317; 25.550

Veliko Tarnovo (Bulgarian: Област Велико Търново, romanized: Oblast Veliko Tǎrnovo) is a province in the middle of the northern part of Bulgaria. Its capital city, Veliko Tarnovo, is of historical significance as it was the capital of the Second Bulgarian Empire. The province is divided into ten municipalities with a total population, as of December 2009, of 275,395.

43°55′N 27°10′E / 43.917°N 27.167°E / 43.917; 27.167

Silistra Province (Bulgarian: Област Силистра, Oblast Silistra) is a province of Bulgaria. Formerly known as the Silistra okrug, it is located on the northeast corner of Bulgaria. The province is part of the Southern Dobrudja region, with its largest and major city being Silistra. As of 2021, the province had a population of 97,770 inhabitants, making it the second least populated in the country. It is divided into seven municipalities for administrative purposes.