Kocaeli Peninsula

The Kocaeli Peninsula (Turkish: Kocaeli Yarımadası) lies in the northwest corner of Anatolia, Turkey, separating the Black Sea and the Sea of Marmara on the Asian side of the strait of Bosphorus.

But while Phrygians and Galatians moved to Central Anatolia, it was the Bithynians who controlled the region for a considerable time.

Hannibal, the Carthaginian commander who took refuge in Bithynia, died in Kocaeli Peninsula [2] at around 182 BC.

In Byzantine times and among the local Greek population until the early 20th century, the peninsula was known as Mesothynia (Μεσοθυνία, "Middle Thynia").

Approximately one-third of Istanbul, one of the most populous cities of the world, lies on the westernmost point of the Kocaeli peninsula, and İzmit, another big city, is at the easternmost point of the peninsula.