Kefalonia or Lefkada?

These are two of the best beach islands in the Ionian, with the same clear turquoise water. The difference is how the beaches are laid out. Kefalonia's are scattered across the island: Myrtos and its white pebbles below the north-west cliffs, Petani and the red sand at Xi on Paliki, Antisamos near Sami, and longer sandy stretches at Skala and Lourdas. You choose a base and drive between them.

Lefkada's famous beaches sit together along the west coast: Porto Katsiki, Egremni, Kathisma and Milos. They face open sea, so expect afternoon waves and a steep drop from the shore. For calm water you go to the east-coast bays around Nidri and Ligia, or to Vasiliki and Agiofili in the south.

Kefalonia gives you more to seek out at the table. It has a cuisine of its own, with meat pie, bourbourelia soup, salt cod with aliada and red mandoles. The Robola wineries of the Omala valley open for tastings, and the harbour tavernas at Fiskardo, Assos and Agia Efimia give dinner a setting.

On Lefkada you eat well but more simply. Look for Eglouvi lentils, the local salami and traditional cooking in villages such as Karya. The resort strips mostly serve standard tourist menus, and neither island goes much beyond Greek food.

Neither island is a culture trip, and both put their sights between beach days. Kefalonia's are scattered: the Venetian fortress at Assos, the Agios Georgios castle, the Mycenaean tomb at Tzanata and the abandoned village of Old Vlachata. Its 1953 earthquake left only Fiskardo with its older houses.

Lefkada's sights are mostly in or near its main town. Santa Maura fortress stands at the causeway, and the town has churches with painted ceilings and timber-topped houses. Beyond the town are the Faneromeni monastery, Karya's embroidery and the Sappho cliff at Cape Lefkatas.

Lefkada has more going on after dinner. In July and August, Lefkada town's lanes fill with cocktail bars and young Greek visitors, Nidri's harbour draws sailing crews, and Vasiliki has its windsurfers' bars. It is still a place for drinks and strolling rather than clubs.

Kefalonia's evenings are quieter and centred on food. Argostoli's square and the Lithostroto stay busy late in summer, and Lassi has a short strip of bars, but most harbours are calm well before midnight.

Both islands are green and mountainous, with tall white cliffs on the west coast, but the outdoor life is different. Kefalonia's is on land and underground: the Mount Ainos national park at about 1,628m, the Melissani and Drogarati caves, and loggerhead turtles in Argostoli harbour and on the southern beaches.

Lefkada's mountains are lower, and its walks are gentler, such as the path to the Dimosari waterfall. It comes into its own on the water, with windsurfing at Vasiliki, kitesurfing in the north and sheltered sailing waters off the east coast.

Lefkada makes the better base for days away. Boats from Nidri reach Meganisi, Kalamos and Kastos, and ferries from Vasiliki cross to Ithaca and to Fiskardo on Kefalonia. Because of the causeway, you can also drive to Preveza, Roman Nikopolis and Parga without a ferry.

From Kefalonia, Ithaca is the one easy outing, a short crossing from Sami. Summer boats reach Zakynthos and Lefkada, and after that most day trips are drives around the island itself.

Families do about equally well on both, and on both the answer is to stay on the calm side. On Kefalonia that means the sandy southern beaches at Skala and Lourdas or Xi on Paliki. Melissani's boat ride and the turtles keep children interested, but the drives to reach them are long.

On Lefkada, base yourself on the east-coast bays or at Agiofili. Short boat trips to the islets are an easy outing, and the west coast's surf and cliff staircases are best kept for an occasional day out.

You need a car on both islands, but Lefkada is a little easier. It is reached by causeway, the airport at Aktion is about half an hour away, and boat taxis cover the nearby islets. Its main delays come from summer traffic through Nidri and the parking at Porto Katsiki.

Kefalonia is larger, and its mountain roads make journeys longer: Argostoli to Fiskardo takes about an hour and a half. The summer ferry from Argostoli to Lixouri does save a long drive around the bay.

On Kefalonia the best things to take home are edible: Robola wine, thyme honey and boxes of mandoles, bought along Argostoli's Lithostroto or in the small boutiques around Fiskardo's harbour.

Lefkada has slightly more to browse. Its town's pedestrian main street has small clothing shops and jewellers, and the village of Karya sells traditional hand embroidery. Outside these places, both islands' resort strips offer little beyond beachwear and souvenirs.

Costs are much the same on both. Lefkada has slightly more cheap studios and few entry fees, while Fiskardo and Assos make Kefalonia's north the dearer end of either island. On both you will pay for car hire and for the August peak, so June or September is the cheaper time to go.

Neither island has much live performance outside summer. Lefkada's August folklore festival brings dance groups from many countries to open-air stages. Kefalonia's music is more local: kantades serenades with guitar and mandolin, and Argostoli's long philharmonic tradition, heard mostly at village festivals and summer concerts.

On both islands, relaxation means the pace of the place rather than spas. Kefalonia has a slight edge. Its larger resort hotels offer more spa treatments, and Paliki and the north-east stay quiet. Lefkada has yoga retreats in the hills, but its busiest resorts are noisy in August, so its interior villages and eastern harbours are the places to stay.