Naxos or Zakynthos?

You can't separate these two on beaches, but they offer different kinds of coast. Naxos has one long chain of fine, pale sand down its west side, from Agios Georgios at the edge of Chora to the dunes of Plaka, Mikri Vigla and Alyko. The water stays shallow a long way out, and there is always an empty stretch somewhere. The catch is the summer meltemi, which can make that open coast choppy for days.

Zakynthos is more varied but more broken up. It has the resort sands of Laganas Bay, the protected turtle beaches of Gerakas and Dafni, coves on the Vasilikos peninsula, and rocky inlets on the west coast where you climb down to swim. Its most famous sights, Navagio and the Blue Caves, are trips by boat rather than places to spend the day, and sunbeds at the resort beaches fill up in high summer.

Naxos eats a little better because it farms so much of its own food. It has potatoes from the fertile valleys, cheeses such as graviera and arseniko, and kitron liqueur distilled in Halki. Meat is grilled in the tavernas of Filoti, Apiranthos and Koronos.

Zakynthos has specialities worth seeking out, such as garlicky skordostoumbi, ladotyri cheese kept in oil, mantolato nougat and Verdea wine. Its resort strips, though, lean towards full English breakfasts. On both islands, the good meals are found inland in the villages.

Here the gap is wide, and Naxos is far ahead. Its history comes in layers: the marble Portara of a temple to Apollo above the harbour, the Venetian kastro with its coats of arms and Cycladic figurines, the unfinished giant kouroi still lying in the quarries at Flerio and Apollonas, and early frescoes in Panagia Drosiani. Seeing it all takes several days of driving.

On Zakynthos, the 1953 earthquake took most of the Venetian capital. What remains is the Byzantine Museum and the Solomos museum on Solomos Square, the church of Agios Dionysios, the castle ruins on Bochali hill and the Anafonitria monastery, which together make a pleasant half day.

Zakynthos has the bigger night out, but it is almost all in one place. The Laganas strip has clubs, promoters and foam parties until dawn, mostly for young British groups. Outside Laganas, the island has family bars in Tsilivi and a few late bars in town.

Naxos is gentler. In summer the harbour of Chora and the lanes below the kastro fill with cocktail and music bars, there are sunset sessions at the beach bars of Agios Prokopios and Plaka, and a couple of clubs stay open late. It suits people who want a drink after dinner more than a big party.

Zakynthos is slightly ahead, and its best scenery is on the coast. There are the high limestone cliffs at Keri and above Navagio, sea caves around Cape Skinari, kayaking and diving, and loggerhead turtles in a national marine park.

Naxos is the island for the mountains. It is the greenest and highest of the Cyclades, with the walk up Mount Zas to around 1,000m, old mule paths between marble villages and empty rocky coasts to the north and east. The same meltemi that makes its beaches choppy turns Mikri Vigla into one of the best kitesurfing spots in the Aegean.

For days off the island, Naxos is clearly better because it sits in the middle of the Cyclades. Paros is under an hour away, the quiet Small Cyclades are easy to reach, Mykonos is the way to Delos, and Santorini is possible in a long day. Strong winds can still cancel boats.

From Zakynthos, the choices are fewer and the journeys longer. In summer there is a ferry to southern Kefalonia, and from the mainland port of Kyllini you can visit the castle of Chlemoutsi or make a long day of ancient Olympia. Most visitors simply tour their own island instead.

Both work well for children, in different ways. Naxos has sheltered, gently shelving sand that toddlers can wade into, Agios Georgios is a walk from Chora, and there is plenty of space even in August. On the other hand, nothing on the island is built for children.

Zakynthos has more laid on. Tsilivi, Planos and Alykes have resort hotels with pools and kids' clubs, there is a water park inland, and children enjoy the turtle-spotting boats. Its downsides are the steep paths down to some famous beaches, hotter midsummer days, and Laganas, which families should stay away from.

Naxos is the easier island to manage without a car. Chora is compact, and in summer buses run along the beach coast to Plaka and up to the main mountain villages. You only need a car or scooter for the remote chapels and the empty east coast.

Zakynthos is only about 40km long, but its buses just link the town with the big resorts. The cliffs, viewpoints and villages of the west and north need your own wheels or an organised boat trip.

Neither island is a place to go shopping, but Naxos has a bit more character. The old market lanes below the kastro have small jewellery, ceramic and linen shops, and Apiranthos and Halki sell weaving and marble work. Zakynthos has Alexandrou Roma street in town, beachwear in the resorts and lace from around Volimes. On both islands, the best things to bring home are food: kitron and graviera from Naxos, mantolato and Verdea from Zakynthos.

Zakynthos is a little cheaper, because it is built around package tourism and that keeps rooms in the big resorts moderately priced. Boat trips, sunbeds and car hire add up over a week, though. Naxos keeps costs reasonable with family-run studios and village rooms, but rooms by the beach and hire cars get noticeably dearer in August. On either island, June and September are the cheapest months to go.

Neither island has a theatre or concert season, but each has its own music. On Naxos it comes from the summer panigyria, village saints' day festivals with island violin and lute, plus a summer festival in an inland Venetian tower. Zakynthos has kantades, serenades sung by groups of men with guitar and mandolin in the tavernas, an old philharmonic band, and omilies folk street theatre at carnival.

Rest on either island comes from the slow pace rather than from spas. Zakynthos has one thing Naxos lacks: cool sulphur springs bubbling into the sea at Xigia, along with spas in its bigger resort hotels. Naxos has a few small yoga retreats on the southwest coast and very quiet hill villages around Halki. On Zakynthos, the calm places to stay are around Keri, Agios Leon and the Vasilikos peninsula.