Kos is located in the south-eastern Aegean Sea south of Kalymnos and north of Nisyros. It is the third largest island in the Dodecanese, its extent 290,29 kilometers.

Kos is the birthplace of the father of medicine, Hippocrates, which was born on the island around 460 B.C. and founded the Great School of Medicine of Kos. The island is famous for its rich vegetation and its temperate climate.