Gyaros, also locally known as Gioura is an arid and unpopulated island in the northern Cyclades near the islands of Andros and Tinos, with an area of 17,574 km2. It is a part of the municipality of Ano Syros, which lies primarily on the island of Syros. This and other small islands of the Aegean Sea served as places of exile for important persons from 1947 to 1952, from 1955 to 1961 and from 1967 to 1974. At least 22.000 people were exiled or imprisoned on the island during these times. It is also an island of great ecological importance as it hosts the largest population of monk seal in the Mediterranean.
There is a red brick prison building which during the years 1948 to 1953 held approximately 10.000 men in custody due to their participation in the Greek Resistance organization Ethniko Apeleftherotiko Metopo (EAM). Many of them were also involved in the Greek civil war (1945–1949). Jehovah's Witnesses were also sentenced to exile there as Christian conscientious objectors.
The prison was used again during the years 1957 to 1964 and during the Greek military junta of 1967-1974. The structures are decaying due to weathering, and no maintenance is conducted. In four separate places north of the prison building, there are also the ruins of the camps where the men lived in tents, both summer and winter.
Once a year, the men and women who are alive and in good health (most of them were born between the 1910s and 1930s) who were formerly imprisoned on the island for their political views pay tribute by visiting the island and holding a ceremony in the cemetery of the men who left their last breath on this island.
The Greek government used the island as a target range for the Hellenic Navy until the year 2000. Currently the island is off-limits to the general public and approaching or fishing in close proximity is forbidden by the coast guard.
The easiest way to visit Gyaros is by contacting the local associations of the Panhellenic Union of National Resistance Fighters (PEAEA) and asking when their next scheduled visit to the islet is going to take place.