Between the resorts of Argostoli and Lassi are the villages of Peratata and Travliata and, above them, the remarkably well preserved Venetian Castle of St George (Agios Giorgios) with coats of arms decorating the massive bastions, one of which conceals a secret tunnel which ran to a lagoon in Argostoli.
The original castle was Byzantine and probably built in the 12th century. The external walls that survive today were constructed by the Venetians in 1504. You can still see cannon placements, observation posts and the remains of a bridge. The castle is usually open in the summer though sometimes closed for restoration work. Check in the village first.
Beneath the castle walls is the Kastro with remains of houses and panoramic views over the island. There are the remains of churches and a welcome cafe, bar and restaurant. Peratata itself is also home to the gorgeous monastery of Agios Andreas filled with 17th-century frescoes and its prize relic, the sole of St Andrew's foot. It also has a notable icon collection.
The road leads to the village of Lakithra, where Lord Byron wrote his epic, Don Juan. The view over the plain below is astonishing, and on a clear day, you can even see the island of Zakynthos.
A few euros lighter, and a suicidal descent down some 120 almost vertical steps, you can find yourself in the cool, damp limestone caves of Drogorati which bristle with stalagmites, stalactites, sodium lamps and camera flashlights.
This is not caving in the raw but the homogenised tourist version, with souvenir shops to help you on your way. The main cavern remains impressive despite the visitor trappings and is even big enough to host the occasional orchestral concert.
Drogarati's Cave was unearthed 300 years ago when a strong earthquake opened up an entrance into it. It's about 60 metres deep and was first opened to the public in 1963.
It appears to be part of an extensive cave system but the surrounding caves are difficult to enter. Many of the limestone stalagmites and stalactites have been broken or damaged, some by earth tremors, others by vandals.
The largest part of the cave is called 'Sala of Apotheosis' a reference to its very good acoustics and the reason it is used for concerts and other performances.
At nearby Melisani, boatmen ferry visitors around an underground lake which has a collapsed roof, virtue of an earlier earthquake.
The underground lake is approached down a long and dark tunnel. Light pouring in from the hole above, and the brilliant aquamarine water below, make for an eerie blue experience.
But the boat ride is very short and highlights are few. Guides are reduced to pointing out the likeness of some of the odd-looking stalactites to the shapes of various zoo animals.
Visitors walk down a steep ramp and through the cave entrance where row boats are moored. Taking a boat ride is the only way to see the Lake Melissani cave.
Melissani is also called the Cave of the Nymphs after ancient artefacts that were found during archaeological excavations in 1951 and thought to be the remains of a Minoan culture. Pottery plates depicted the god Pan and several nymphs – hence the name.
Lake Melissani is nearly a half a kilometre from the sea and a mixture of salt and fresh water. Another cave system adds fresh water to the sea water raising the surface to about a metre above sea level. The water is about 100 feet deep so don't fall in. It flows sedately from one end of the B shaped cave to the other, entering another narrow cave system to emerge into the sea at Kalovethres.
The best time to see the spectacular light effects from the hole in the roof is at midday when the sun is directly overhead but the effect is impressive at just about any time provided the sun is out. Sunshine hits the turquoise water and floods the cave with a brilliant blue light. Where the water went was once a great mystery – solved in 1959 by tracking the slow current with dye.
The picturesque setting in a beautiful bay makes this one of the main landmarks on Kefalonia though the castle itself is a bit of a disappointment. Now listed as a European Heritage Site the castle sits on a promontory above the village about 35 kilometres north of Argostoli.
Bigger than the other Kefalonia castle, that of Agios Giorgios, Assos has two kilometres of walls that circle the hilltop in a rough rectangle dotted with five bastion towers.
Building began in 1593 by the Venetians and the idea was to establish a city within its walls to defend the whole island but a lack of water meant it was vulnerable to sieges and plans were soon scaled down.
The was used as a prison farm until 1953 and prisoners built terraces and planted vines and olive trees. The inner kastro housed about 200 families until the late 1960s when the castle was abandoned.
Visitors can still see the remains of the prison yard and the cells and there are still some ruins of an army barracks built by the Germans during the war as well as a church known as the 'French Church'. Another ruined church built in 1888 is in very poor repair.
Assos village below is a sleepy place that sits at the end of some very scary hairpin bends. A small central square overlooks a strand of sharp sand. Many of the original buildings lost in earthquakes have been replaced by modern chocolate box designs.
Mount Ainos is the main mountain range of Kefalonia and the third highest in Greece with a peak at 1,626 metres. It was declared a National Park in 1962 and it's a great place for nature lovers and hill walkers.
There is a six-kilometre walking trail through the park but it is rough, tough going and at the highest point, just where you need a cantina, only has some radio masts and NATO radar station.
The hillsides are known for the long, pencil-thin endemic Kefalonia pine trees and, if you are really lucky, you might catch a glimpse of the wild horses that live on the southeastern slopes. Pretty much wherever you are you will get amazing views over the island.
A lot more impressive inside than it is out the Museum of Archaeology at Argostoli has a fine collection of Mycenaean, Roman and Hellenistic relics and treasures from all over Kefalonia.
Highlights are the sculpted platter found in the Melissani Caves and a 3rd Century Roman bust of bronze. Various military artefacts, war weapons and uniforms of occupying forces are also to be found the Korgialenos Cultural and Historical Museum.
Nearby is the Koryialeno Folk Museum, which features local costumes, furniture and embroidery, as well as paintings, maps, jewellery and local crafts. The museum also houses a library and Kefalonia's historical archives with rare manuscripts from the 16th to the 19th centuries and many photos of Argostoli before it was wrecked by the island earthquake in 1953. The library displays highlight all aspects of 19th-century life on the island including costumes and lacework, tools and household utensils.
Also worth a visit is the Natural History Museum in Davagata; rather small but with a fascinating natural history of Kefalonia' s flora, fauna down the geological ages.
Kefalonia has it's fair share of monasteries worth visit while on holiday and these are the main ones.
In the valley of Omalon is Monastery of Agios Gerasimos, probably the most important religious place on the island as this is the patron saint of Kefalonia and where they keep his bones in a silver casket. Gerassimos was from Corinth and was known for his healing powers especially with the mentally ill.
There are a small chapel and the well decorated main church as well as a cave where Gerassimos lived most of his life. The saint is celebrated each year with a feast day on August 16 when there are singing, dancing and a procession of the saint's sarcophagus.
Also boasting the saint's remains is the Monastery of Agios Andreas, just up the hill from Svoronata village. First built in Byzantine times it was adopted by Andrew in 1579. A beautiful place to visit, there are some fine artefacts in the museum, from the foot of St Andrew to the shroud of Gregorios the Fifth as well as some fine frescoes and a famous painting of Romila and her parents.
The Monastery of Atros is the oldest on Kefalonia and dates from the 8th century. It has been damaged or destroyed no less than 17 times through war, earthquakes and fire, so it's a bit of a survivor. It sits on top of Mt. Atros at about 770 metres about seven kilometres out of Poros. There is a medieval tower and an 'archodariki' or 'welcome hall' but currently, only one monk lives there to welcome you. Getting there is a delight. It is one of the best walks on Kefalonia, with fine vistas over Poros.
Above Lourdas beach us the Monastery of Sissia founded by Saint Francis of Assisi in the 13th century. Very wealthy and influential in its time it has some remarkable icons and frescoes. In 1676 an annual march was made to it from the Castle of Saint George. Unfortunately, the original building was destroyed by the 1953 earthquake and a new monastery built next to the ruins.
The Monastery of Kipoureon is found 15 kilometres from of Lixouri on the Paliki peninsula, founded in the late 16th century with a fantastic collection of Byzantine icons and church relics. The once beautiful gardens have gone but the grounds and pine wood surroundings are very peaceful while the views over the coastline are memorable.
Near Argostoli are the Katavothres swallow holes where water disappears into underground caverns to emerge on the other side of the island. The water funnelling in and out at each end has been used for generations to power waterwheels. How seas water should continue to flow is really quite baffling and the phenomenon is extremely rare. After all, the water should simply find its own level and stop flowing. But flow it does from one end to the other with waterwheels at both ends.
Both Kaligata and Domata are known for their good church interiors as well as the local wine.
Around the mountain at Agia Dynami are found goats with silver teeth – a result of minerals that stain the animals' mouths. Not that you can get anywhere near the creatures to take a look.
Markopoulis clings to the side of Mount Ainos and is undistinguished but for the annual ritual of hundreds of harmless tiny snakes that appear around the church every summer. Each August 15 they head for the icon of the Virgin in the church and vanish. A bit like the island's tourists really.