The Kızılırmak River, also known as the Halys River in ancient times, is the longest river in Turkey. It stretches approximately 1,355 kilometers (842 miles) and flows through central Turkey, eventually emptying into the Black Sea. The river is significant for its historical importance and its role in the region's agriculture. The Kızılırmak is known for its reddish color, which is derived from the clay and sediment in its waters. It passes through several cities, including Kayseri and Sivas, and supports various ecosystems along its banks. The river is also vital for irrigation and provides water for local communities.