Kos or Cos (Greek: Κως) is a Greek island of the group of the Dodecanese, next to the Gulf of Gökova/Cos. The island measures 40 by 8 kilometres (25 by 5 miles), and is 4 km (2 miles) from the coast of Bodrum, Turkey, and the ancient region of Caria. The island constitutes a municipality within the Kos regional unit, which is part of the South Aegean region. The principal town of the island and seat of the municipality is Kos town.