The Cyclades Islands form an archipelago of islands scattered across the Aegean Sea. This archipelago stretches from the coast of mainland Greece in the far northeast to Crete in the west. The archipelago takes its name from the arrangement of its islands, which form a circle around Delos, a sacred island listed as a UNESCO World Heritage Site. The Cyclades Islands cover an area within a roughly 370-mile-wide circle. Not all of the Cyclades Islands are inhabited.

The Cyclades Islands are mountainous islands, some of which are of volcanic origin.

The Cyclades archipelago is made up of numerous islands, 56 in total, with barely half of them inhabited. The different islands sometimes form chains or groups depending on their geographical location.

The western islands of the Cyclades extend along a general northwest-southeast axis in the western part of the archipelago, between the Athens region and the central Cyclades. Kea, Kythnos, Serifos, and Sifnos are among the main islands in this area. Closer to mainland Greece than Santorini, they offer a variety of landscapes, alternating between arid hills, valleys, traditional villages, cliffs, and beaches. Less homogeneous than their belonging to the Cyclades might suggest, each island has its own character and offers a different side of the archipelago.

The central islands of the Cyclades include Gyaros and Syros, located in the heart of the archipelago. Syros is the larger of the two, with Ermoupoli, the capital of the Cyclades, known for its remarkable neoclassical architecture. Nearby, Gyaros offers a striking contrast with its arid landscape and wild character. This uninhabited island, once used as a place of political exile, is now protected, notably for its population of Mediterranean monk seals.

The northern islands of the Cyclades include Andros, Tinos, Mykonos, Delos, and Rhenia, in the northern part of the archipelago. These islands offer varied landscapes, from mountains and valleys to beaches and rocky coastlines. Andros and Tinos stand out for their traditional villages and rolling landscapes, while Mykonos is known for its whitewashed villages and lively summer atmosphere. Delos and Rhenia, located near Mykonos, offer a very different experience, with the ancient ruins of Delos and the wild landscapes of Rhenia.

The central islands of the Cyclades include Paros, Antiparos, Naxos, Keros, and the Small Cyclades, in the heart of the archipelago. Paros and Naxos are the two main islands in this group, with their traditional villages, beaches, and agricultural landscapes. Across from Paros, Antiparos offers a more peaceful atmosphere, while uninhabited and protected Keros is best known for its archaeological importance. Southeast of Naxos, the Small Cyclades form a group of islands and islets with arid landscapes, secluded coves, and unspoiled beaches.

The southern islands include Amorgos, Folegandros, Ios, Kimolos, Milos, and Sikinos, along with Astypalaia, located at the eastern end of this group. These islands offer varied landscapes, from cliffs and arid hills to beaches and traditional villages. Amorgos and Astypalaia stand out for their mountainous landscapes, while Milos and Kimolos are known for their volcanic origins. Folegandros, Ios, and Sikinos, meanwhile, offer wilder landscapes and villages typical of the Greek islands.

The islands at the southernmost end of the Cyclades include Anafi and Santorini, at the southern edge of the archipelago. Santorini is the better known of the two, with its spectacular volcanic caldera, cliffs, and whitewashed villages overlooking the Aegean Sea. More secluded, Anafi offers a wilder landscape, with arid hills, cliffs, and unspoiled beaches. These two islands form one of the southern gateways to the Cyclades, close to Crete.

The Cyclades archipelago also includes a multitude of uninhabited islands and islets, numbering several hundred or even more, depending on the criteria used to identify and count them. Some of the best known include:

The Cyclades can be reached directly by air, with several airports located on the islands of Milos, Mykonos, Naxos, Paros, Santorini, and Syros. These flights make it possible to reach some of the islands from Athens, while Mykonos and Santorini also have seasonal international connections.

Ferries, however, remain the main way to reach the many islands of the archipelago. Regular services connect the port of Piraeus, near Athens, as well as other Greek ports with the main Cycladic islands. Ferries then make it possible to continue traveling from one island to another, with frequencies and crossing times varying depending on the route and season.