Zonguldak, city, capital of Zonguldak il (province), northwestern Turkey, on the Black Sea coast. The well-equipped port is the main outlet for coal extracted from the basin between Zonguldak and Ereğli.
The city’s development and rapid rise in population were associated with the growth of this coal industry after the mid-19th century. Mining was extensively developed by the government after 1940, and much of the city’s workforce has remained engaged in work
related to coal.