 Along its western side flows Eşen Çayi, "the Esen River," anciently the Xanthos, Lycian Arñna, originating in the Boncuk Mountains, flowing south, and transecting the several-mile-long beach at Patara.The Xanthos Valley was the country called Tŗmmis in dynastic Lycia, from which the people were the Termilae or Tremilae, or Kragos in the coin inscriptions of Greek Lycia