Kocaeli is in the Marmara region and most often known for its district center Izmit. The ancient name of Kocaeli was Nikomedia, which dates back to 8th century BC. There are remains from Roman and Byzantine times that can be seen in Kocaeli - including citadel, Temple of Augustus and agora. These pieces are mostly decayed but some findings from excavations nearby can be found at archaeology museum near here.
Izmit is an industrialized area of Turkey with a variety of tourist pursuits associated with it. Some places popular among tourists are Kartepe, a winter ski resort at 1600 meters in height, Kerpe and Kefken, Black Sea shore towns that boast excellent beaches, while Golcuk and Karamursel are sea resorts in the Gulf of Izmit. There are three parks in the city; along side amusement parks there is outlets shopping as well.
One of the towns of Kocaeli is Hereke, where the very best Turkish carpets are produced. The artistic carpeting in Ottoman palaces were woven here only for sultans. These carpets are valued and well-known all around the world.