Beyond Platani and four kilometres to the southeast of Kos Town stands the island's most famous and exciting ancient site, the Asklepeion.
Kos' native son Hippocrates is rightly remembered with street names, statues, a medical centre and even a tree but he is most wholly celebrated at this ancient sanatorium, founded in 444BC not long after his death and now a major tourist attraction.
It was both a temple to the Asklepios, the god of healing and a renowned Hellenic medical centre that functioned for about 1,000 years before falling into disrepair.
The setting is magnificent, elevated on hillside terraces that are connected by a monumental marble staircase. It sits above the village of Anatolia on four terraces linked by a marble staircase, with views over the sea to Turkey.
Little of the original centre remains, thanks in large part to repeated earthquakes and the use of the site as a quarry by the Crusaders. It was extensively excavated by Germans in 1902 and the Italians re-erected some Corinthian columns dating from the 2nd century. A Doric temple, built some 400 years earlier sits on the highest terrace.
Local guides love to elaborate on the Hippocratic connection but the famous healer's life story is elusive, and his links to Kos are very tenuous. He was undoubtedly born here in 460 BC, and he also died here in 357 BC.
But he spent most of his life away from Kos, travelling throughout the Aegean and advocating his 'scientific' approach to medicine, gaining fame by halting plagues through the then-novel practice of boiling drinking water and isolating the sick.
From the main square in Kos Town at Plateia Platanou a bridge crosses the Finikon dry moat to the Castle of the Knights, also called the Kastro tis Neratzias. The castle was built by the Knights Templar in the 14th century along with similar fortifications in Rhodes as a defence against the Ottomans.
The fortress, with its massive outer walls, was surrounded by a large moat but damaged by an earthquake in 1495 then restored in the 16th century. Much of the stone taken to build it was snatched from the ancient Agora.
Visitors enter through the well-preserved 16th-century gateway and a walk around the remains of its inner walls, with the views of the harbour, is a favourite of Corfu visitors. Take care of the kids though as there is little in the way of safety features.
Over the drawbridge is a circular tower with 15th-century carvings and to the north an old knights' building, probably a warehouse, restored by the Italians who occupied the island from 1912 to 1947.
The ancient town, with its widespread and impressive ruins, is located right in the heart of Kos Town. They comprise an ancient city wall and several sanctuaries with well-preserved mosaics.
The Western Excavation
The Western Excavation is on Grigoriou Street, a 10-minute walk west from the centre and boasts the island's oldest archaeological remains. There are two large covered areas at the back for mosaics from the 'House of Europe' and a stretch Roman road 'Decumanus Maximums' as well as the Roman Nymphaeum (actually Roman urinals) and the 'Xysto' gymnasium. It also features some imposing colonnades, several courtyards, ancient baths and a temple to Dionysos. The recently restored Roman Odeon amphitheatre is near.
There is a lot less to see of the Ancient Agora site as much of the stone was taken away to build Kos castle. But to the west are the remains of the Stoa (Great Hall) and to the north several intriguing ruins including the Temple of Hercules, the 5th-century Christian Basilica, and also the Shrine of Aphrodite.
Also called Palaio Pyli, the Castle of Antimachia is in the centre of the island about 25 kilometres from Kos Town.
Built in Venetians times, it passed into hands of the Order of the Knights of St John and consists of the castle ruins and two old churches. There is a good road to the castle which is not too far from the tourist resorts of Kefalos and Kardamena.
It looks more impressive outside than in as the inner area is very shabby and in poor condition. There is not much to see inside apart from two Venetian churches; Agios Nikolaos dates from the 16th century and Agia Paraskevi, built in the early 18th century, but there are extensive views of the surrounding area.
Near the north coast Kos resort of Mastichari is the Hippocrates' Garden cultural centre. The centre is a modern replica of an ancient 5th-century BC Greek settlement that would have existed at the time that the 'father of medicine' Hippocrates would have lived and worked.
There is an ancient Greek house of 'okios, an arcade typical of those where Greek philosophers would have walked and talked, an amphitheatre to stage theatrical productions, some museums, a botanical garden and a replica temple.
The centre was built in 2008 to promote ancient Greek culture and history, and it attracts hundreds of Greek schoolchildren each year as well as many holiday tourists.
As well as displays on Greek social history, philosophy, and ancient medicine, visitors can learn about more modern concerns such as recycling, wildlife protection and the Mediterranean diet.
Visitors can get there down a 1.5km dirt track, but there is a campaign to raise funds to pave the road. For more details visit the centre website at www.hippocratesgarden.gr
Pserimos is a small island about halfway between Kos and Kalymnos. It would be an idyllic place but for the day trippers that descend in droves throughout the season. A few lucky visitors can find rooms to stay but not many among a mere 30 or so houses.
The main beach on the island is at Avlakia, a lovely stretch of golden sand, quickly covered in sun-bedded bodies. Day-trippers arrive like locusts and snap up all available sun beds.
They also pack the tavernas and make a noisy addition to what would otherwise be a peaceful islet. Even the ferries have been known to queue to tie up to the small quay. Those boats that can't find a berth head off to neighbouring Platys which has a similar, but smaller, sandy beach and far fewer trippers.
There are a couple of other beaches, not as attractive but much quieter. One is at Vathy in the north, reached with a 30-minute walk along a well-marked path to a cove of sand and pebbles. Another is at Marathounda to the west, a 45-minute walk to a pebble cove. The island is so small that nowhere is more than an hour's step in any direction.
Day-trippers make up almost all the visitors as there is so little accommodation on the islet. There are rooms to be had above the tavernas and one small store which gets stocked up by the daily boat that leaves Pothia on Kalymnos around 9 am each day. Nearly all the other boats that pull in are on daily cruises between Kos and Kalymnos with a stop here and at Platys.
A boat trip to the island of Nisyros or Nissyros is very enjoyable. It has active volcanic fumaroles, steam vents, boiling mud and sulphur. The island also has a charming village with narrow streets, bougainvillaea and many other beautiful flowers.
Local travel agents charge much less than the big tour operators for trips to the island, and smaller boats and tour parties can make for a more peaceful trip.
The walk up the crater is a bit scary with very steep and unfenced drops and don't go in plastic flip-flops – they can melt off your feet.