The islands are the main characteristic of Greece’s morphology and an integral part of the country’s culture and tradition. Greek sovereign land includes 6,000 islands and islets scattered in the Aegean and Ionian Seas, of which only 227 islands are inhabited. This is a truly unique phenomenon for the European continent.
The Greek Archipelago takes up 7,500 km of the country’s total 16,000 km coastline, offering a highly diversified landscape: beaches stretching over many kilometers, sheltered bays and coves, sandy beaches with sand-dunes, pebble beaches, coastal caves with steep rocks and dark colored sand typical of volcanic soil and coastal wetlands.
Many of these Greek beaches have been awarded the blue flag under the Blue Flags of Europe Program, providing not only swimming, but also scuba diving, snorkeling, water skiing, sailing and windsurfing.
Some of the oldest European civilizations developed on the Greek islands (Cycladic, Minoan civilizations, etc.), so therefore the islands have unique archeological sites, a distinctive architectural heritage and the fascinating local traditions of a centuries-old and multifaceted civilization.
The ideal climate, safe waters and small distances between ports and coasts, have made the Greek islands extremely popular among Greek and foreign visitors.
Most of the islands are found in the Aegean Sea and are divided into seven groups (from north to south):
The Northeastern Aegean Islands
Agios Efstratios, Thasos, Ikaria, Lesbos, Limnos, Inouses, Samos, Samothrace, Chios, Psara.
Alonissos, Skiathos, Skopelos, Skyros
The prefecture of Evia (which also includes the island of Skiros), is next to the prefecture of Viotia on the east and on the south touches the Aegean Sea, on the north and northwest to the Pagasitiko and Maliako Gulf, while on the west and southwest with the north and south Evian Gulf.
Islands of Argosaronic
Angistri, Aegena, Methana, Poros, Salamina, Spetses, Hydra.
A group of 56 islands, with the most important being Amorgos, Anafi, Andros, Antiparos, Delos, Ios, Kea, Kimolos, Kythnos, Milos, Mykonos, Naxos, Paros, Santorini, Serifos, Sikinos, Sifnos, Syros, Tinos, Folegandros, as well as the “Minor Cyclades” comprising Donousa, Irakleia, Koufonisia and Schinousa.
Astypalaia, Kalymnos, Karpathos, Kasos, Kastellorizo, Kos, Lipsi, Leros, Nisyros, Patmos, Rhodes, Symi, Tilos, Chalki.
Crete is divided in to four prefectures. From west to east: Chania, Rethymno, Heraklion and Lasithi.
The Ionian Sea has only one island complex:
The Ionian Islands
Zakynthos, Ithaca, Corfu, Kefallonia, Lefkada, Paxi, and Kythira which is situated opposite the southern Peloponnese (Laconia). These islands, which are the biggest of the Ionian Sea, constitute the famous Eptanissa (meaning seven islands; epta in Greek means seven).
Antipaxi, Ereikoussa, Kalamos, Kastos, Mathraki, Meganissi, Othoni, Skorpios, Strofades are smaller islands of the Ionian Sea.
The islands of Gavdos (situated south of Crete), Elafonissos (in the Gulf of Laconia) and Trizonis (in the Gulf of Corinth), do not forme a group but are still of unparalleled natural beauty.
Source : http://www.visitgreece.gr/en/greek_islands