Lüleburgaz, Bergoule or Arcadiopolis is the largest city of Kırklareli Province in the Marmara region of Turkey. It is the seat of Lüleburgaz District. Its population is 125,404 (2022). Located near the border with Bulgaria and Greece within the historic region of East Thrace in Rumelia, the city is home to many Balkan Turks from Albania, Bulgaria, Greece, Romania and ex-Yugoslavia who immigrated to Turkey since the 19th century.

Kırklareli Province is a province in northwestern Turkey on the west coast of the Black Sea. The province neighbours Bulgaria to the north along a 180-kilometre (110 mi) long border. It borders the province of Edirne to the west and the province of Tekirdağ to the south and province of Istanbul to the southeast. Kırklareli is the capital city of the province. Its area is 6,459 km2, and its population is 369,347 (2022). The province's and its central city's name means "the land of the forties" in Turkish and it may refer either to the forty Ottoman ghazis sent by the sultan Murad I to conquer the city for the Ottoman Empire in the 14th century or to the forty churches reported to be situated in the region before the Ottoman conquest, as attested by the former name of Kırklareli. There is a memorial on a hilltop in Kırklareli city, called "Kırklar Anıtı" to honor the Ottoman conquerors. The province is bisected by the Yıldız (Istranca) mountain range. The north and northeastern parts of the province are among the least populated and under developed parts of Turkey. The districts to the south and west are more populated because the land is better suited for agriculture and industrial development. The north and eastern parts of the province are dominated by forests. Therefore, forestry is an important means of living in these areas. Fishing is done along the Black Sea coast.