The Cyclades are a group of Greek Islands, located in the southern part of the Aegean Sea (south of Athens and north of Crete). The archipelago contains some 2,200 islands, islets and rocks; just 33 islands are inhabited. The Cyclades are best known for the islands of Santorini and Mykonos.
Ermoupolis (Syros) is the capital of the Cyclades.
Most of the Cyclades have one main town which has the same name as the island. Some larger towns which have names of their own include:
The Cyclades are the Greece of the travel posters: bare rocky islands adorned with brilliantly white cubistic villages soaring on hills above the wine-dark sea, and fringed with terrific beaches. Since all the world has discovered this, they tend to be very crowded with visitors, especially in high summer. But most visitors feel the islands' attractions are worth putting up with the crowds.
Kyklos is the Greek word for circle. Because the islands are set up in a circle around Delos the islands are named Cyclades. The best time to visit the Cyclades is May through June (early season, accommodation is much cheaper and it's not that hot), or September through mid-October (post season). In high summer (July and August), though it's the most popular season, these islands for that reason get extremely crowded and hotel prices are at their highest; furthermore, the weather then can be very hot, and some islands may suffer water shortages. In the whole period mid-May through mid-October it's usually warm enough to enjoy the beaches, but in some years you risk unseasonably chilly weather at the beginning or end of this period. In October the weather changes and rain starts to fall. Ferry schedules are reduced out of season. The Cyclades are also famous for the constant wind (called meltemi) in July and August that mitigates the heat a bit.
Regular (mostly daily) flights from Athens to Mykonos, Paros, Naxos,Santorini,Milos and Syros operated by Olympic Air  and Aegean Airlines . In high season there are also less frequent flights from Rhodes, Crete (Heraklion) and Volos by Sky Express . From May till October charter airlines fly directly to Santorini and Mykonos from many European airports.
From the Greek mainland ferries and highspeed catamaran services  run daily from Piraeus, Rafina and Lavrio. Ferrys operate to all the islands in the Cyclades, some of the larger islands also have a highspeed catamaran service. Ferry trips are four to five hours to the closest islands (Kythnos, Syros, Tinos, Mykonos and Sifnos) and from eight to ten hours to the furthest (Santorini) depending on the number of stops. The highspeeds take half the time but cost twice as much. There are daily ferries from Pireaus to all of these islands, with the exception of Kea and Kythnos which you get to from Lavrio and Andros which you get to from Rafina.
Many travelers probably consider Rafina not a possible departure port if they are heading to one of the Cyclades, but if you are arriving at the airport of Athens, you are often better off taking a ferry from Rafina than traveling to Athens and get a ferry from Piraeus.
Many boat services stop working by end of October and resume by April. Check with the operator before making departure plans as the services are subject to delays and cancellations in adverse weather.
Ferry schedules 
Travel by ferry. They are safe, regular, cheap and fun. The biggest ferry hub within the Cyclades is in Paros which has links to many islands.
Be prepared that travelling by ferry can be tedious in high season when ferries are really crowded. Usually there are two types of ferries: The ordinary ones and the speedboats (hydrofoils, which are much more expensive).
Also, ferries may be cancelled due to sea and weather conditions so don't leave on the last ferry before your flight, especially if it is windy. Seas are calmer at night, so the late evening and early morning ferries are the most likely to operate.
Tickets for ferries can be usually bought from travel agencies which are located around the local port.
See Greece#Eat for more information on Greek cuisine.
If visiting in winter season, try Ρακόμελο (pronounced rakomelo). The local people drink this hot drink to warm them up on a cold day. Ingredients are raki, honey and hot water. Recommended that you only drink one or at most two. Drink three and you will be ready for bed!
The Cyclades are very safe. Travelers should exercise usual precautions.
Be aware of rental scams, especially with agencies working only with motorbikes and ATVs. Using these types of vehicles is very common on Cyclades and there are a lot of rental agencies. Some of them are ready to cheat. They will offer faulty motorbikes or ATVs for a lower price, but in case of accident they will demand that the customer pay for the whole cost of damage. They are offering only basic insurance but will present it like full insurance. Also, there is a big possibility of serious injuries.
It is possible to recognize these rental agencies by observing them aggressively attracting tourists and offering lower prices than others. Employees in front of these type of agencies will be loud and ready to promise everything until the contract is signed. It is necessary to check the vehicle before making any decision. Their vehicles are in most of the cases dusty, dirty and look old.
Head on down to Crete when you are done with the Cyclades. If you have plenty of time you might want to go to other Greek islands belonging to the Dodecanese, the Ionian Islands or the Sporades as well.