The Seyhan River is a major river in Turkey that flows through the city of Adana. There are several synonyms for this river depending on the language and region. In Turkish, it is known as Seyhan Nehri or Seyhan Irmağı. In Arabic, it is called Nahr al-Sīhān, and in Greek, it is known as Kalykadnos. The river has also been referred to as Sarus in ancient texts. The Seyhan River is the longest river in Turkey that flows into the Mediterranean Sea, and it serves as an important source of irrigation and hydroelectric power for the region.