Kos or Cos is a Greek island in the group of the Dodecanese, next to the Gulf of Gokova - Cos. It measures 40 kilometres (25 miles) by 8 kilometres (5.0 mi), and is 4 kilometres (2.5 miles) from the coast of Bodrum, Turkey and the ancient region of Caria. The island has both fertile plains and mountainous highlands with a population of 30,947. It comprises three municipalities: Kos, the administrative center and largest town (pop. 17,891), Dikaio, and Irakleides.
Historians accept that Hippocrates was born around the year 460 BC on the Greek island of Kos (Cos), and became a famous physician and teacher of medicine. Other biographical information, however, is likely to be untrue (see LegendsSoranus of Ephesus, a 2nd-century Greek gynecologit was Hippocrates' first biographer and is the source of most information on Hippocrates' person.

The island is part of a chain of mountains from which it became separated after earthquakes and subsidence that occurred in ancient times. These mountains include Kalimnos and Kappari which are separated by an underwater chasm c. 70 m (40 fathoms deep), as well as the volcano of Nyssiros and the surrounding islands.
There is a wide variety of rocks in Kos which is related to its geographical formation. Prominent among these are the Quaternary layers in which the fossil remains of mammals such as horses, hippopotami and elephants have been found. The fossilised molAr of an elephant of gigantic proportions was presented to the Paleontology Museum of the University of Athens.
The shores of Kos Island are washed by the waters of the Aegean Sea. Its coastline is 112 km long and is caressed by long immaculate beaches, leading to its main industry being tourism. Farming is the principal occupation of many of the island's inhabitants, with their main crops being grapes, almonds, figs, olives, and tomatoes, along with wheAt and corn. Cos lettuce may be grown here, but the name is unrelated.
The main villages of Kos island are Kardamena, Kephalos, Tingaki, Antimachia, Mastichari, Marmari and Pyli. Smaller ones are Zia, Zipari, Platani, Lagoudi and Asfendiou.

The main port and population centre on the island, also called Kos, is also the tourist and cultural centre, with whitewashed buildings including many hotels, restaurants and a small number of nightclubs forming the famous Kos town "barstreet". The town has a 14th century fortress at the entrance to its harbour, erected in 1315 by The Knights of Saint John of Rhodes.
The ancient physician Hippocrates is thought to have been born on Kos, and in the center of the town is the Plane Tree of Hippocrates, a dream temple where the physician is traditionally supposed to have taught. The limbs of the now elderly tree are supported by scaffolding. The small city is also home to the International Hippocratic Institute and the Hippocratic Museum dedicated to him. Near the Institute are the ruins of Asklepieion, where Herodicus taught Hippocrates medicine. Kardamena is a popular resort for young British holidaymakers and has a large number of bars and nightclubs