# Kythnos Sights: Castles, Caves, Springs & Monasteries > Kythnos sights include the Venetian Castle of Oria, the ancient capital of Vriokastro, the kilometre-long Katafiki Cave at Dryopida, the thermal springs of Loutra, the prehistoric settlement of Maroulas and the monasteries of Panagia Nikous and Panagia Kanala. | | | |---|---| | Old capital | Vriokastro | | Longest cave | Katafiki (~1 km) | | Thermal springs | Loutra | | Landmark | Panagia Nikous | **Kythnos sights include the Venetian Castle of Oria, the ancient capital of Vriokastro, the kilometre-long Katafiki Cave at Dryopida, the thermal springs of Loutra and the monasteries of Panagia Nikous and Panagia Kanala.** Kythnos rewards travellers who explore its bare brown hills, where ruined capitals, a long cave, hot springs and whitewashed monasteries tell the island's long history. Hire a car to explore Kythnos at your own pace, covered in our [Kythnos car hire guide](https://fly2greece.net/car-rental/kythnos.html). _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ _Photo: Sights of the island of Kythnos, Cyclades, Greece_ ## Sights of Kythnos Kythnos keeps its sights across a bare, rocky landscape, from two ruined capitals to a long cave, hot springs, a prehistoric settlement and a set of monasteries. The Venetian Castle of Oria and the ancient city of Vriokastro record the island's old capitals. The Katafiki Cave and the settlement of Maroulas reach back to prehistory, the thermal springs of Loutra have drawn visitors since antiquity, and the monasteries of Panagia Nikous and Panagia Kanala and the Byzantine museum at Dryopida hold its religious treasures. ## The Castle of Oria The Castle of Oria is a Venetian castle on a mountain top in the north of Kythnos, standing just before Cape Kefalos. It was the old capital of the island until the Turks destroyed it in 1570, when the Venetians moved to Messaria. Some remains of the castle walls, of houses and of two churches survive, though the castle is hard to find because the path leading to it is unclear. ## Vriokastro: the ancient capital Vriokastro lies in the north-west of Kythnos, the remains of the island's old capital. It was a large city, inhabited from the 10th century to the beginning of the 7th century BC, and some sections of its thick city wall are still intact. Excavations have found a temple of Demeter, an acropolis and other buildings, and in 2001 another temple was uncovered on the site, yielding about 1,500 objects, including jewels and pieces of gold, silver, coral, glass, ivory and semi-precious stones. ## Katafiki Cave & Maroulas The Katafiki Cave near Dryopida is, with its length of about one kilometre and its several underground lakes, one of the longest caves in Greece, though it is not always open to visitors. Maroulas is a settlement near Dryopida that dates from 9000 to 8000 BC. Excavations at Maroulas have uncovered round dwellings and unearthed skeletons and stone tools. ## Loutra thermal springs Loutra, on the north coast of Kythnos, is a 19th-century spa and fishing village named for its hot springs, which have been used as a spa since antiquity. The thermal water rises beside the beach, and a few hotels stand nearby, making Loutra the island's second base after Merichas. It is a quiet stop that pairs a swim in the sea with the warm mineral springs; the hotels here are set out in the [Kythnos hotels & villas guide](https://fly2greece.net/kythnos-hotels.html). ## Monasteries: Panagia Nikous & Panagia Kanala The Monastery of Panagia Nikous is the landmark of Kythnos, found 800 metres from Chora and pictured on all the postcards of the island. It is large, white and walled, standing alone in the bare brown landscape, and legend tells that it once housed an icon which, after the fall of Constantinople, was brought here and is now kept in Saint Mark's in Venice. The Monastery of Panagia Kanala stands on a rock near the village of Kanala and holds an icon of the Virgin Mary that the Greeks believe can work miracles; it is richly decorated and has beautiful murals. ## Byzantine Museum, Dryopida The Byzantine Museum of Kythnos is housed in the Agios Georgios church in Dryopida. This small museum holds special and old icons, a quiet stop in the traditional village of Dryopida, close to the entrance of the Katafiki Cave. Explore Kythnos [Kythnos guide](https://fly2greece.net/kythnos.html) [Kythnos Hotels](https://fly2greece.net/kythnos-hotels.html) [Kythnos Beaches](https://fly2greece.net/kythnos-beaches.html) [Kythnos Restaurants](https://fly2greece.net/kythnos-restaurants.html) --- Source: [Kythnos Sights: Castle of Oria, Katafiki Cave, Loutra Springs & Monasteries](https://fly2greece.net/kythnos-sights.html) — fly2greece.net, an independent guide to Greece written and photographed by Hans Huisman since 2000. Reviewed July 2026.