Sakarya is a province and metropolitan municipality in Turkey, located on the coast of the Black Sea. Its area is 4,824 km2 (1,863 sq mi), and its population is 1,110,735 (2024). The Sakarya River creates a webbing of estuaries in the province, which is in the Marmara Region. The adjacent provinces are Kocaeli to the west, Bilecik to the south, Bolu to the southeast and Düzce to the east. The capital of Sakarya is Adapazarı. Its climate is maritime in the north and humid subtropical in the south and changes by the distance to the Black Sea. Sakarya is on the Ankara-Istanbul highway and is also connected by rail. Sakarya is serviced by Istanbul's Sabiha Gökçen International Airport. The mayor of Sakarya is Yusuf Alemdar as of 2024 (AKP). The city of Sakarya, one of the most important cities in Turkey for its rapid growth and development, is known for its natural surroundings and culture. Home to several resort towns, Sakarya has access to the sea, beaches, lakes, rivers, highlands, thermal springs, traditional Ottoman lifestyle districts such as Taraklı and Geyve and noteworthy historical relics from the Byzantine and the Ottoman eras. The Turks conquered the city of Sakarya in the