Kefalonia or Rhodes?

Both islands have excellent swimming in very clear water, but the beaches look and work differently. Kefalonia's best beaches are its dramatic ones: Myrtos and Petani, white pebble below cliffs and green slopes, with sand at Skala, Lourdas and the reddish beach at Xi. They are spread across different coasts, so you end up driving between them.

On Rhodes, the beaches you'll actually use run in one continuous line down the sheltered east coast, from Faliraki through Tsambika to Lindos, where you can stay in one place and walk or bus to the next bay. The beaches are less spectacular than Myrtos and the busiest ones fill with sunbeds, but the water is calmer and there's more sand.

The two islands are about equal for food, and on both the best meals are long, simple ones in family tavernas. Kefalonia has a stronger local identity, with its meat pie, aliada with salt cod and red mandoles, and Robola wine you can taste at the wineries of the Omala valley.

Rhodes has its own dishes too, such as pitaroudia, slow-cooked goat and souma, but it takes more effort to find them because the resort strips mostly serve buffets and repeated menus. In practice, you eat better there in the inland villages and the local meze places of Rhodes Town.

On culture the two islands are far apart. Rhodes has one of Europe's most complete medieval fortified towns, with the Street of the Knights, the Palace of the Grand Master, and mosques and a synagogue inside the walls. Beyond the town there's the cliff-top acropolis at Lindos and ancient Kamiros, together several days of real sightseeing.

Kefalonia lost most of its old buildings in the 1953 earthquake. Fiskardo's Venetian-era harbour, the fortress ruins at Assos, the tomb at Tzanata and abandoned Old Vlachata make good half-day outings, but none of them is a reason to choose the island.

Rhodes has the livelier evenings by a wide margin. Faliraki's strip of bars and clubs runs until dawn in high summer, a lane of bars in the Old Town stays open late, and Lindos has rooftop and courtyard bars for an older crowd.

On Kefalonia, a night out means a long dinner and then a drink on Argostoli's Lithostroto, at the beach bars of Lassi or by the harbour at Fiskardo. Clubs are few and small, and outside July and August most places are quiet before midnight.

Kefalonia has the more striking scenery. Mount Ainos rises to about 1,628m, and its national park of Greek fir has semi-wild horses and wide views over Ithaca. Underground there's the Melissani lake cave and the Drogarati chamber, and loggerhead turtles feed in Argostoli harbour. Sea kayaking and sailing to Ithaca round it out.

Rhodes is gentler, with low pine-covered hills, the shaded Valley of the Butterflies and Seven Springs. Its outdoor strength is wind: Prasonisi, at the southern tip, is one of the Mediterranean's best-known windsurfing and kitesurfing spots, and nothing on Kefalonia compares.

Rhodes has the better boat trips. Symi's pastel harbour, often combined with the monastery of Panormitis, is a classic day out. Quiet Halki is a short crossing from Kamiros Skala, and the ferry to Marmaris takes you to Turkey for the day.

Kefalonia's best outing is Ithaca, a short ferry ride from Sami, for Vathy, Kioni and the sites linked to Odysseus. Summer boats also go to Zakynthos and Lefkada. On both islands most crossings run only in the warmer months.

Rhodes is the easier choice with children. The bays at Tsambika, Afandou and Kolymbia shelve gently into calm water, the big east-coast hotels are set up for families with pools and kids' clubs, and the water park above Faliraki and the aquarium in Rhodes Town fill a day when the beach gets dull.

Kefalonia works if you stay in the south near Skala or Lourdas, or on the Paliki peninsula near Xi, because the famous north-west pebble beaches drop off quickly. The boat through Melissani and spotting turtles go down well, but there are no attractions made for children, and the drives in summer heat are long and winding.

Rhodes is much easier without a car. Rhodes Town's Old Town is compact and car-free, buses run steadily along the east coast to Faliraki and Lindos, and boats for Symi leave from Mandraki. Many visitors only hire a car for a few days.

On Kefalonia a car is close to essential. The mountainous island spreads its beaches and caves across different coasts, the drive from Argostoli to Fiskardo takes about an hour and a half on winding roads, and buses are too infrequent to plan around. The summer ferry from Argostoli to Lixouri saves one long drive.

Neither island is worth visiting for shopping, though Rhodes has more to browse. Sokratous Street in the Old Town is lined with jewellery, leather and sponge stalls, and you can buy Lindian-style painted ceramics in Archangelos and lace in the villages.

Kefalonia has Argostoli's Lithostroto and a few boutiques around Fiskardo's harbour. Its best souvenirs are things to eat and drink: Robola wine, thyme honey and boxes of mandoles.

Costs are similar on the two islands, and both are mid-priced for a Greek island in summer, with July and August the most expensive months. On Kefalonia, Skala, Lourdas and Lassi offer fair value while Fiskardo and Assos cost more, and almost everyone also pays for car hire.

On Rhodes, the large supply of package and all-inclusive hotels keeps the east coast moderate, and the buses save some of that car hire. Lindos is the island's expensive corner.

Neither island has a theatre, opera or regular concert season, so plan around chance events. Kefalonia has a musical tradition of its own: kantades serenades with guitar and mandolin, and Argostoli's long-standing philharmonic band, both best heard at village festivals and summer concerts in the squares.

Rhodes is more about the setting than local music. There's a folk dance company in the Old Town and summer concerts in the medieval moat and the ancient stadium.

On both islands pampering means a resort hotel spa, and neither has a bathing tradition. On Rhodes, the Kallithea rotunda is a sight, not a place to bathe. The difference is in where to go to slow down. On Kefalonia, it's the Paliki peninsula, the north-east coast and harbour evenings in Assos.

On Rhodes, you need to head south, to villages such as Lahania, Asklipio and Gennadi, well away from the noisy resort strip in the north.