Kocaeli, an industrial city, is surrounded with orchards and vegetable gardens. The city, which was known as “Nicomedia” in the Roman era, and its surroundings, are full of historical works remaining from the Ottoman era.

One of the counties of the city, Hereke, is famous for carpet weaving. As for Gebze, located on the northern shores of the Marmara Sea, it has rich historical assets, including the tomb of the famous Carthaginian commander Hannibal.

Sakarya, with its extensive plains and fertile lands for agri-culture, is an industrial center too.