Islands & island-hopping
There are around two hundred inhabited Greek islands in six groups, and they have almost nothing in common with each other. Choosing the group is the single most consequential decision in planning a Greek trip.

About Islands & island-hopping
The Cyclades are the bare ones — white cubes, no trees, hard light, strong wind. The Ionian are green and Venetian, with cypress running to the water. The Dodecanese are medieval and Italian. The Sporades are pine forest. Crete is a country. The Saronic islands are an hour from Athens and have no cars.
Island-hopping sounds romantic and often is not. Ferries eat days, and three islands in a week means three arrival afternoons and three departure mornings — roughly half the holiday spent in transit. Two islands in seven nights is the honest maximum; one island and a private boat is frequently better than either.
The other rule: hop within a group, not across them. The ferry networks are radial, so Naxos to Milos is easy and Naxos to Rhodes is a day and a change in Piraeus.
Where it is at its best
Two islands, one week
Cyclades
One famous, one quiet, linked by a 40-minute ferry. The most reliable island week there is.
One island, one boat
Milos or Paxos
Stay put and let a private caïque do the moving. No packing, no timetables.
The no-car islands
Hydra
Mules and boats only, ninety minutes from Piraeus, and quiet from ten at night.
September
Everywhere
Warm sea, thinning crowds, full ferry timetable. The best month in the Aegean.
Regions for this

Cyclades (classic)
Santorini, Mykonos, Paros, Naxos. Famous for good reason, and entirely manageable if you get the hours right.
Cyclades (off-grid)
Milos, Folegandros, Sifnos, Amorgos, Serifos, Kimolos. Same light, same sea, a fraction of the people.

Crete
Not an island so much as a small country: four mountain ranges, a Bronze Age civilisation, and its own kitchen.
Ionian (Eptanese)
Corfu, Kefalonia, Lefkada, Zakynthos, Ithaca, Paxos. Green, Venetian, and the closest Greek islands to Malta.

Dodecanese
Rhodes, Symi, Patmos, Karpathos, Nisyros. Medieval, Italian, monastic — the Aegean's most layered islands.
Sporades
Skiathos, Skopelos, Alonnisos, Skyros. Pine forest to the waterline and Europe's largest marine park.
Athens & Argo-Saronic
The city, the coast below it, and four islands an hour from the port — Hydra, Spetses, Aegina, Poros.

Halkidiki & Thessaloniki
Three peninsulas of pine and clear water, and the best eating city in Greece behind them.