Zonguldak is a city and the capital of Zonguldak Province in the Black Sea region of Turkey. It was established in 1849 as a port town for the nearby coal mines in Ereğli and the coal trade remains its main economic activity. According to the 2009 census, Zonguldak has a population of 108,792. The city’s name probably comes from Zone Geul-Dagh, the name given to the area by French and Belgian mining companies. Göldağı (“Lake Mountain”) is the highest mountain in the vicinity of Devrek district. Following information about Ereğli coal mining history, will help us to understand Zonguldak name is originated from Zone Geul-Dagh in French: (In Catholic Encyclopedia, with reference of year 1908, Zonguldak town is called as “Zoungoul-Dagh” or in Turkish, Zoungoul mountain; or with Turkish+French meaning, Lake/Göl mountain zone… “Goul-Dagh is a mountain on the south of Zonguldak town, with a little lake… It was a reference benchmark for the new mining zone and sea port location in Ereğli region after 1860s.”) Summers are warm and humid, and the average temperature is around 21°C in July and August. Winters are cool and damp, and the average temperature is around 6°C in January and February. Precipitation is heaviest in autumn and early winter and lightest in spring. Snowfall is quite common between the months of December and March, snowing for a week or two, and it can be heavy once it snows. The water temperature like in the whole Turkish Black Sea coast is always cool and fluctuates between 8° and 20°C throughout the year.