Agia Kioura (Saint Matrona) in Leros is one of the most unique, moving, and historically significant landmarks on the island. Located in the northern part of Leros, near Partheni Bay, it sits in an isolated and serene landscape. This 18th-century church has been officially designated as a protected monument and a historic work of art by the Greek Ministry of Culture due to its extraordinary backstory and unconventional iconography.

During the military dictatorship in Greece (1967-1974), the area of Partheni served as a concentration camp for political exiles. Among the detainees were numerous artists, writers, and intellectuals. On the initiative and through the hard labor of the exiles themselves, the then-dilapidated church of Agia Kioura was restored and completely repainted by the exiled artists Antonis Karagiannis, Kyriakos Tsakiris, and Takis Tzaneteas.

The frescoes inside the church are globally unique, departing sharply from strict, traditional Byzantine iconographic rules. The artists used their fellow prisoners, everyday cellmates, and local islanders as real-life models for the Saints, the Virgin Mary, and Jesus Christ. The faces of the figures reflect the physical exhaustion, deep pain, sorrow, and ultimate resilience of the political prisoners, transforming the small chapel into a universal symbol of freedom, human dignity, and artistic resistance.