In the city of Kos the monuments of ancient times are separated into 3 zones: the excavations of the port, the central and western zone. The finds in the first zone which came to light after the earthquake of 1933 include the Stoa (4th or 3rd century B.C.), the sanctuary of Hercules (3rd century B.C.), the small sanctuary, the double sanctuary of Pandimos and Aphrodite Pontias, the Agora and finally the famous plane-tree of Hippocrates which comprises an offshoot of the original tree in the shade of which, according to tradition, the father of medicine taught and wrote many of his writings. In the central zone there are relics of a Minoan settlement and of the Geometric Age.
Included in the zone are structures with beautiful mosaics (3rd century B.C.), the ancient Stadium (2nd century B.C.), the Western Bath Houses (2nd-3rd century B.C.) the "Xysto" Gymnasium, the Nymphaeum (3rd century B.C.), the House of the abduction of Europa with the homonymous mosaic, the Roman conservatory, the Altar of Dionysus and the restored Roman House (Casa Romana).
At a distance of 3.5 km southwest of Kos, there is the most famous and long standing monument of Kos, the Asclepeion. During ancient times the Asclepeion was a sacred hospital and this specific one was considered the most significant since it had a history of many centuries. It started to be built during the 4th century B.C. and in the same place findings were discovered from the Minoan and Geometric periods. It is laid out in three levels: On the first are the Propylaea, Bath House ruins, Stoas and Public Lavatories. On the second there is the most ancient temple of the Asclepeion (3rd century B.C.), the altar of Asclepeion or of Apollo of Kyparissia (4th century A.D.), remains of a temple of Apollo (3rd century A.D.) with seven restored pillars. Finally, on the third level there are ruins of the great temple of Asclepeion (2nd century B.C.) and traces of Hellenistic Stoas.
At Pyli there is a said tomb of Harmylos, a total of 12 tombs in a dome-shaped structure. At Kefalos, there are still ruins of a Hellenistic theater at the site of Palatia, 3 km to the south.