Kythnos is one of the closest Cycladic destinations and enchants the visitor not only with its beaches and hospitable inhabitants, but also with the abundance of monuments that are scattered in the area. The monuments of Kythnos belong to a wide historical spectrum since they chronologically span from prehistoric times (Maroulas), historical times (Vryoskastro) and the Middle Ages (castle of Oria). At the same time there are several shipwrecks which are an ideal destinations for diving enthusiasts.
The archaeological site of Maroulas is particularly important since it is the only outdoor settlement of this period (9,000 – 8,000 BC) that has been found in Greece. Houses and burials have been found in the area, while among the remains there are obsidian, quartz and flint tools.
Vryokastro is one of the most popular archaeological destinations of Kythnos. It was inhabited from the 12th century BC until the 7th century AD when it was abandoned by the inhabitants who moved to the castle of Oria. An acropolis, two cemeteries, underground reservoirs, a port as well as a multitude of public buildings have been found in the area.
The Castle of Oria, the medieval capital of the island, is still waiting for the archaeologists to discover its secrets. It is located in an impressive and secluded location on the northwestern tip of the island. Its habitation began in the 7th century AD and continued until the 16th century, when it was conquered by the Turks.
The waters of Kythnos are home to several shipwrecks, the most important being the Pepe in the bay of Agios Stefanos, which is an ideal hiding place for the fish of the area, and the Niki, a World War II cargo ship which is also in the same bay.