Kocaeli Province (, ) is a
province of
Turkey. Its capital is
Izmit, which is also sometimes called Kocaeli. The province is the successor of the
Ottoman-era
Sanjak of Kocaeli. The largest towns in the province are
Izmit and
Gebze. The traffic code is 41. The province is located at the easternmost end of the
Marmara Sea around the
Gulf of Izmit. Kocaeli is bordered by the province of
Istanbul and the Marmara Sea to the west, the
Black Sea to the north, the province of
Sakarya to the east, the province of
Bursa to the south and the province of
Yalova to the southwest. The metropolitan area of Istanbul extends to the Kocaeli-Istanbul provincial border. The size and natural conditions of the Bay of Izmit allow for extensive port facilities, including the
Gölcük Naval Base. The province is called the industrial capital of Turkey. Kocaeli has an airport named
Cengiz Topel Naval Air Station which is used for military and civilian transport. Kocaeli has two universities:
Kocaeli University and
Gebze Technical University.