Milos or Mykonos?

These are two of the strongest beach islands in the Aegean, but the beaches differ in kind. On Milos the beaches are volcanic and mostly undeveloped: the white pumice of Sarakiniko, the long sandy south-coast bays such as Firiplaka and Paliochori, and some coves you can reach only by boat. Many have no sunbeds or shade.

Mykonos is the organised version. Psarou and Platis Gialos are lined with loungers, Paradise and Super Paradise are known for their party crowds, and Elia and Kalafatis give you more room. On both islands the north wind sends swimmers to the south coast in high summer.

Mykonos has the wider table. Alongside harbour fish in Little Venice and local specialities such as peppery kopanisti cheese and louza, a cured pork, it has a large scene of sushi, fusion and chef-led dining, though that is often more about being seen than about eating well.

Milos keeps to Cycladic taverna cooking: grilled octopus in Klima, pitarakia cheese pies, ladenia flatbread and a few ambitious sunset kitchens in Plaka. It is honest food, especially in the inland villages, but you will find almost nothing international.

Delos makes the difference. The sacred island of Apollo, with its Terrace of the Lions and mosaic-floored houses, is a morning's boat trip from Mykonos. Chora's windmills, Paraportiani church and small museums add to it.

Milos has more heritage than its size suggests: early Christian catacombs, the field where the Venus de Milo was found, a marble Roman theatre and the Bronze Age site at Phylakopi. None of it matches Delos, though, and two days covers it all.

The two islands are opposites after dark. Mykonos runs from loud afternoon sessions at Paradise and Super Paradise to cocktail bars in Chora's lanes, a long-established gay scene and clubs with international DJs until sunrise, all at full pitch in July and August.

Milos ends its day with the sunset from Plaka's castle hill, a long dinner and a drink on the harbour in Adamas or Pollonia. A few bars stay open late in high summer, but there is nowhere to dance until dawn.

Milos has the more striking landscape, all of it shaped by its volcano. The coast has pumice ravines at Sarakiniko, red and yellow cliffs at Firopotamos and Papafragas, and the rock towers and caves of Kleftiko, best seen by sailing boat or kayak. Inland, waymarked trails lead to the abandoned sulphur mines at Paliorema.

Mykonos is low, brown and nearly bare, and its walks are country lanes out to places like the Armenistis lighthouse. Its real outdoor asset is the meltemi, which makes Korfos Bay and Kalafatis good for kitesurfing and windsurfing. It also has reefs and wrecks for diving.

Mykonos sits at the centre of a busier ferry network. Delos is right on its doorstep, Tinos is half an hour away with its pilgrimage church and marble-carving villages, and Syros, Paros and Naxos are each about an hour away.

From Milos the choice is smaller. The easy outing is a short crossing from Pollonia to quiet Kimolos, and in summer the fast boats make Sifnos possible. On both islands, wind and timetables decide what works.

Milos is the slightly easier choice with children, mainly because the whole island is calm. Provatas and Paliochori shelve gently into the sea, and Pollonia has a sheltered beach in the village itself. It has no attractions made for children, though, and many beaches are reached by dirt track or boat.

Mykonos does have a water park near Elia and a Delos trip that older children enjoy. Its identity is built around adult nights out, however, so families do best at a quiet bay like Ornos or Agios Stefanos.

Mykonos is somewhat easier without your own wheels. Chora is a car-free maze you walk, buses run to the main south-coast beaches and Ano Mera, and sea taxis shuttle between Platis Gialos, Ornos and the bays beyond. Taxis are scarce in summer and traffic around town gets heavy.

On Milos the summer buses reach only Plaka, Pollonia and a few beaches, so you need a car or quad. Even then, the western half is on rough dirt roads, and Kleftiko is reached by boat. Getting to the island is harder too: a long ferry from Piraeus, or a short flight from Athens.

Mykonos has real shopping, if a narrow kind. Matoyianni Street and the lanes around it are full of designer resort wear, swimwear, fine Greek jewellery and galleries, and the shops stay open late into the evening. It is ideal for building a beach wardrobe.

Milos offers a browse at best: a few linen and ceramics boutiques in Plaka on the way to the sunset, and souvenir shops in Adamas. Its capers, honey and sweets are the best things to bring home.

Neither island is cheap in summer, but Milos is the gentler bill. Rooms in Pollonia and Plaka are costly in July and August, yet an ordinary taverna meal is fairly priced, and simple rooms in the inland villages bring the cost down.

Mykonos is among the most expensive places in Europe for a vacation. Hotels, beach-club sunbeds, cocktails and taxis are all priced for a luxury crowd. Gyros counters, public buses and rooms around Ano Mera help, and on both islands June and September cost less.

Neither island has a theatre, opera or concert season, so neither is worth choosing for the stage. What you can hear is different, though. On Milos it is the summer panigyria, village saints'-day feasts with violin and lute late into the night, plus the occasional concert at the ancient theatre. On Mykonos the music is the club and beach-bar DJ sets, with an occasional open-air concert or village festival.

Milos is the more restful island, and its volcano helps. You can soak in the rustic public baths at Lakkos in Adamas or the springs near Provatas, and at Paliochori the sand is warm where steam escapes. Beyond that, the slow mornings and long dinners do the rest.

On Mykonos, wellness means massages and terrace yoga at the upmarket hotels. The island's summer rhythm of beach clubs and late nights works against rest, so anyone wanting calm should head to Agios Sostis, Ftelia or the bays beyond Kalafatis.