Updated October 2026
Kythnos is a quiet Cycladic island, also spelled Kithnos, that you can reach from Athens in under two hours by ferry from Lavrio. It is the only island in the Cyclades with thermal springs, and it has Kolona, a sandbar beach with the sea on both sides. Life here is slow, and there is no party scene.
This guide covers how to get to Kythnos, how the hot springs at Loutra work, the best beaches and villages, how to get around, and when to go.
| Fact | Details |
|---|---|
| Where | Western Cyclades, between Kea and Serifos |
| Size | About 100 km² |
| Population | 1,568 (2021 census) |
| Main port | Merichas |
| Capital | Chora, also called Messaria |
| Ferry from Lavrio | About 1 hour 10 minutes to 1 hour 45 minutes |
| Ferry from Piraeus | About 3 hours |
| Known for | Hot springs at Loutra, Kolona beach, Katafyki cave |
Locals also call the island Thermia, a name recorded as early as 1143. It comes from the hot springs, which are still the island's best-known sight.
The island has a long story. People lived here in the Mesolithic period, more than 10,000 years ago. In ancient times Kythnos was home to the painters Timanthes and Kydias, and Aristotle wrote a study of its constitution that has since been lost. In the Middle Ages the capital stood at the Castle of Oria, until it moved to today's Chora.
You can only reach Kythnos by sea. Ferries leave from two ports near Athens: Lavrio and Piraeus. Lavrio is the faster choice, and it is about an hour's drive from the city centre or a short drive from Athens airport.
| Route | Journey time | Notes |
|---|---|---|
| Lavrio to Kythnos (direct) | About 1 h 10 min to 1 h 45 min | Fastest. Time depends on the boat. |
| Lavrio to Kythnos via Kea | About 2 h 30 min to 3 h | Some boats stop at Kea first. |
| Piraeus to Kythnos | About 3 hours | Easy if you are staying in central Athens. |
Times are from the Greek National Tourism Organisation and recent traveller reports. Ferries run daily in high season, but there are fewer boats in spring and autumn, so check the timetable before you plan.
Kythnos also connects with Kea, Serifos and Sifnos, which makes it an easy first stop on a Western Cyclades trip. If you are choosing between nearby islands, see our guide to Kea and our list of Greek islands near Athens.
The Kythnos hot springs are in Loutra, a small village in a sandy bay on the northeast coast. It is about 11 km from Chora, around 20 minutes by car from Chora or the port. The water is rich in sulphur and iron, and it comes out of the ground at 35°C to 52°C, according to the Greek National Tourism Organisation.
There are two springs, and they work in very different ways.
The Agioi Anargyroi spring rises inside the Hydrotherapy Centre, a 19th-century building run by the Municipality of Kythnos. Here you can book individual baths, use small pools and try other wellness treatments. The centre opens seasonally, from May to October.
The history is part of the visit. The first bath house was built here in 1782. Later, King Otto and Queen Amalia came to Loutra for treatment, and the main spa building was finished in 1857. Their mansion still stands in the village.
About 50 metres away, the Kakavos spring flows straight into the sea. Its water also contains iodine, bromine and salt. Where the hot stream meets the bay, it forms a natural warm pool in the sea, and anyone can sit in it for free.
Tips for the springs:
Kythnos has dozens of beaches, from easy sandy bays near the port to remote coves at the end of dirt roads. These are the ones to know.
Kolona is the most famous beach on the island. A thin, curved strip of sand runs out into the sea, so you can swim on either side of it. If one side is windy, try the other.
You can get there by a rough track road or by water taxi from Merichas. In 2025 the water taxi cost €14 return and took about 15 minutes. There is no shade, so bring water, food and sun cover, and go early or late in the day.
Martinakia, Episkopi and Apokrousi are the easiest beaches to reach from the port. They have fine sand and some facilities, so they are good for families and for a first swim after the ferry.
On the east coast, look for Liotrivi, Skyliou, Simoussi, Gaidouromantra and Petrousa. On the west coast, Agios Dimitrios and Flabouria are good choices. Most of these need a car, and some are at the end of unpaved roads.
Chora (Messaria). The capital is built like an amphitheatre on the hillside and has changed little since the 17th century. It is a good place for an evening walk and dinner.
Dryopida. The second inland village, close to Katafyki cave. The small Folklore Museum shows furniture, costumes, tools and a traditional loom from island homes.
Merichas. The port and the main base for most visitors, with rooms, tavernas and the water taxi to Kolona.
Loutra. The hot springs village, with a small harbour and the spa buildings.
Kanala. A seaside settlement with the church of Panagia Kanala and its much-loved icon of the Virgin Mary. In August, pilgrims come for its festival.
Explore Katafyki cave. Near Dryopida, Katafyki is one of the largest caves in Greece. People first visited it in the 1830s, it was an iron mine until 1939, and today it is open to visitors.
See Maroulas. Near Loutra, this is one of the oldest known settlements in the Cyclades, dating from about 10,000 to 8,000 BC. Excavations found stone tools, floors and human skeletons.
Walk to the Castle of Oria. On the northern headland stand the ruins of the island's medieval capital. It stands on a steep rock at about 250 metres and was abandoned in the 17th century. The ruins have not been excavated, so visit with care.
Count the chapels. Kythnos has around 130 small white churches. Finding them is a good excuse to explore by car.
Rent a car. This is the easiest way to see the island. If you plan to rent a car in Kythnos in July or August, book early, because prices are higher in peak season.
Scooter or ATV. Good for narrow village roads, but take care on dirt tracks.
Local buses. There are local buses, but they are limited outside July and August. Outside high summer, do not rely on them.
Water taxi. The best way to reach Kolona from Merichas in summer.
Where you stay depends on what you want from the island.
June and September are a good balance. The island is calmer than in August, and the Hydrotherapy Centre is open.
July and August are the busiest months. August brings Greek families, sailing boats and the Panagia Kanala festival. High summer can also be windy.
May and October are calm and quiet. The Hydrotherapy Centre is still open, though some tavernas and rooms may be closed. You can still sit in the free Kakavos sea pool, so a swim in cooler weather still feels warm.
November to April is very quiet, with fewer ferries. Check what is open before you book.
Kythnos food is simple and local. Try sfougato, small fried balls made with the island's soft fresh cheese. Look for kopanisti, a sharp, creamy cheese spread, and the island's thyme honey. Local tavernas also serve slow-cooked meat with potatoes, sun-dried fish and strapatsada, eggs with zucchini or tomato. Ask for local wine to go with it.
Yes, if you want a real Greek island without the crowds of the famous Cyclades. Kythnos is close to Athens, quiet, and has something no other Cycladic island has: natural hot springs you can swim in for free. It is not the place for nightlife or luxury shopping.
Take a ferry from Lavrio, near Athens airport, or from Piraeus. From Lavrio the trip takes about 1 hour 10 minutes to 1 hour 45 minutes. From Piraeus it takes about 3 hours.
The Kakavos spring, which flows into the sea at Loutra, is free and open to everyone. The baths inside the Hydrotherapy Centre, fed by the Agioi Anargyroi spring, are a paid service and open from May to October.
No. Kythnos is a quiet, family-friendly island with tavernas and a few relaxed bars. People come for the beaches, the hot springs and the slow pace.
Two or three days is enough to see Kolona, the springs at Loutra, Chora and Dryopida. Add a day if you want to explore the quieter beaches by car.
Kythnos is the island near Athens with hot springs you can swim in: a short ferry ride, a warm sea pool, and quiet villages. If you want to add it to a longer trip in Greece, our team can plan the ferries, the stay and the days in Athens around it. Tell us about your trip and we will design it with you.
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