Kocaeli is a dynamic industrial province in northwestern Turkey, straddling the eastern shore of the Marmara Sea and the Gulf of İzmit. Known historically as Nicomedia, it served as capital of the Eastern Roman Empire. Today it balances heavy industry with natural beauty—dense beech forests in Kartepe, pristine Black Sea coves, and a rich layered history from Byzantine to Ottoman eras. Visitors find a city largely bypassed by mass tourism yet rich in genuine Turkish urban life, affordable food, and easy access to Istanbul.
Transport tips
Travel smarter, not harder.
Buy multi-day or weekly transit passes if you'll use public transport more than twice a day.
Keep small change handy for buses and shorter trips where contactless may not work.
Avoid rush hour (typically 7-9 AM and 5-7 PM) for a more comfortable journey.