Kocaeli Province is a province of Turkey. It does not have the same official name as its capital, İzmit, which is sometimes called Kocaeli. The largest towns in the province are İzmit and Gebze. It is at the eastern end of the Sea of Marmara around the Gulf of İzmit. Kocaeli is next to 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. Istanbul goes to the Kocaeli-Istanbul provincial border. The Bay of İzmit has 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.