The Gyzi Megaron Museum is situated in the Halls of the Cultural Centre, where the following permanent collections are hosted.
- A collection of authentic engravings with maps, landscapes and dresses of the Cycladic islands from the 15th until the 19th century.
- A collection of old public and private historical manuscripts of Santorini. The exhibition hosts documents from the Archives of the Catholic Diocese of Santorini, which has been divided into two large sections, relating to the State and the Church respectively.
- The state-related section contains approximately 3,500 documents, wills, transactions, marriage contracts, testimonials, estate benefits, property exchanges and loans.
- The ecclesiastical section contains documents related to the administration of the Catholic Church, but mainly contains archives of weddings, baptisms and deaths.
In general, it includes private and public texts, written mostly in Greek and even the local dialect. However, there are also some texts written in Osmanli Turkish, Latin and Italian. The documents presented here were selected in order to cover a broad spectrum of public and private life on the island between the late sixteenth and the early nineteenth century.
- A collection of paintings, donated to Gyzi Megaron by Caliopi & Leon Pintos couple.
- A collection of Santorini photographs
- A collection of Santorini rocks & minerals
- A folklore collection donated to Gyzi Megaron by Nikos & Konstantinia Tsitsa couple.