Kocaeli, located in the Marmara region, is most commonly associated with its central district, Izmit. This region has a rich history dating back to the 8th century BC, when it was known as Nikomedia. Visitors can still see remnants of its Roman and Byzantine past, including the citadel, Temple of Augustus, and agora. While many of these historical sites have decayed over time, artifacts from nearby excavations can be viewed at the local archaeology museum.
Izmit is a heavily industrialized area in Turkey, but it also offers numerous attractions for tourists. Kartepe, a winter ski resort situated 1600 meters above sea level, is a popular destination, as are Kerpe and Kefken, coastal towns on the Black Sea known for their beautiful beaches. Additionally, Golcuk and Karamursel offer seaside resorts in the Gulf of Izmit. Visitors can also enjoy the city's three parks, amusement parks, and outlet shopping.
Hereke is a town in Kocaeli that is famous for producing the finest Turkish carpets. These luxurious carpets were originally created exclusively for Ottoman sultans and were used to decorate their palaces. Today, they are highly valued and renowned throughout the world.