Kocaeli is the city that takes place on the highway and railroad connecting Istanbul to Anatolia. The name of the city was Nicomedeia in the times of Roman Empire. Today it is a very industrial center for Turkey. The largest town in the province is now Gebze. There are lots of harbour of harbour facilities within Kocaeli, including the primary base of the Turkish Navy.
Kocaeli was founded by Phrygian King Nicomedes the 1st in 262 BC, under the name of Nicomedia. The city was the metropolis of Bithynia under the Roman Empire, and Diocletian made it the eastern capital city of the Roman Empire in 286. Nicomedia remained as the eastern (and most senior) capital of the Roman Empire until Licinius was defeated by Constantine the Great in 324. Constantine mainly resided in Nicomedia as his interim capital city for the next few years, until in 330 he declared the nearby Byzantium as Nova Roma, which eventually became known as Constantinople. Until the late XI century the city was under Byzantine rule. Than it was captured by Seljuk Turks. After capture of Constantinople in 1204 the city, together with most of the Bithynia province, became a part of the Latin Empire. It was recaptured by the Byzantines around 1235 and stayed in its borders until first half of the XIV century. The city was conquered by the Ottomans in 1338 and still is a Turkish land. In Kocaeli has the typical urban summer with hot and dry, and the winter is wet.

Places to Visit ;

Mosques and Theological Schools Orhan Mosque is in the Orhan district, on a hill that is overlooking the city. The mosque had been founded by Süleyman Pasha in the times of Orhan Gazi in 13th century. The mosque had been restored by Ottoman Emperor Abdülmecit.

Fevziye Mosque takes place in the Hürriyet Street of Kemalpaşa District. It had been founded by Mehmet Bey in 16th century. The mosque had collapsed in the earthquake in 1884, and reconstructed.

Pertevpaşa Theological School is one of the most important architectural buildings of İzmit. The School is at the both sides of Yeni Cuma Street. The School had been made by Architecture Sinan in the 16th century. The school consists of a mosque, Caravan Palace and Aşevi (Soup Kitchen) Çoban Mustafa Paşa Theological School had been founded by Mustafa Pasha, who was a vizier of Yavuz Sultan Selim and Süleyman the Magnificent, in Gebze. It had been built by Architecture Sinan and Architecture Acem Ali in the 16th century as a theological school for the "Menzir Dervishes".

The complex consists of a mosque, inn, pasha residences, charitable establishment, school, library, bath, and tombs. It is an example for the theological school complexes, which the additions had been constructed after the construction of the main building has finished. Bridges Kuzuyayla when you reach to Kuzu Yayla, by taking the road full of pine, beech, and lime trees, and colorful flowers, you can observe how the fresh air, panoramic sightseeing, and wild nature are blended. It is a mountain that has a sea view. Kelpeze region here is an other beautiful place which the visitors can make use of both in summer and in winter. Promenade Kuzuyayla when you reach to Kuzu Yayla, by taking the road full of pine, beech, and lime trees, and colorful flowers, you can observe how the fresh air, panoramic sightseeing, and wild nature are blended. It is a mountain that has a sea view. Kelpeze region here is an other beautiful place which the visitors can make use of both in summer and in winter.

Beaches Kerpe is a cute Black Sea Village which is 10 km away from Kandıra, and 50 km away from İzmit. The beauty of the landscape is unbelievable with its blue sea and the pine trees in the mountains. Kerpe is a place which is not effected by the great waves of Black Sea. The sea is very shallow here, and the shores are so beautiful. Kefken is 20 km away from kandıra. It is very suitable for shore residence. Similar to Kerpe it has a wonderful beach and pine forests. İt is a very popular place for the scuba - divers and for the underwater hunters. Cebeci, which is 27 km away from Kandıra; Sarısu, which is 8 km away from Kandıra Bayramoğlu and Eskihisar which is 6 km away from Gebze are the other beaches of the city.

Thermal Springs Süleyman Pasha Thermal Bath takes place in the Yukarı Pazar district of İzmit. It had been constructed in the 14th century. It is the oldest Ottoman building in the region. Yazlık Thermal Spring, which is 15 km away from Gölcük, Maşukiye Spring in Maşukiye and , and Soğuksu Spring in Bahçecik are very popular places of the area.

• Basiskele
• Cayirova
• Darica
• Derince
• Dilovasi
• Gebze
• Golcuk
• Izmit
• Kandira
• Karamursel
• Kartepe
• Korfez