Armutlu Peninsula density in the mountains at the inner peninsula is low, where there are only small villages. Both gulfs at the north and the south are actually on two active tectonic fault lines. The entire peninsula was hit by the İzmit earthquake on August 17, 1999 that occurred along the western portion of the North Anatolian Fault Zone. Armutlu Peninsula Armutlu Peninsula () is a peninsula extending westward into Marmara Sea in the Anatolian section of Turkey. In addition to Yalova Province, parts of Kocaeli Province and Bursa Province are on the peninsula. Armutlu Peninsula is between Gulf of Izmit in
Datça Peninsula small peninsula which is nearly an island, connected to the mainland by a low, 100m-wide spit of land; in antiquity it was a man-made causeway. The ancient name of the island was Triopion, after Triopas, the legendary founder of Knidos. The peninsula's eastern end is Bencik Cove, about 1.5 km in length and sometimes referred to as a fjord on the basis of local scales, and at the end of its indentation is the narrow isthmus where Datça Peninsula joins the Anatolian mainland is found. This point is a natural curiosity which offers a wide view of the two gulfs