The Cheshmeh Kileh River is located in the northern part of Iran. It flows into the Caspian Sea at Tonekabon city. Its headwaters comprise two forested valleys, Do-Hezar ("Two Rivers") valley and Se-Hezar ("Three Rivers") valley, both on the northern slopes of the Alborz mountain range. The outflows from these valleys have a confluence at a place called Chaldehra or Chaldarreh, about 24 kilometres (15 mi) south of Tonekabon, and this forms the Cheshmeh Kileh proper.