The church of St. Nicholas of Kasnitzis is located near the Byzantine acropolis of Kastoria near the Omonia Square. It is an important monument of the 12th century in Kastoria. Three founder’s inscriptions inside the church give us information about its history. On the eastern wall of the narthex, the founder of the church, magistrate Nikiforos Kasnitzis, a member of the local aristocracy, is depicted with his wife Anna dedicating an effigy of the church to the honoured saint of the church.
It is a small, one-room church with a narthex. Little light enters the interior, as there are three monolobe windows. The interior of the monument is inscribed. Among other things, there are scenes from the Dodecaorton, the Prayer (Supplication), the life of St. Nicholas and full-length figures of soldiers and other saints.
The study of the painting confirms the important position of Kastoria as an artistic, economic and cultural centre in the region of Greater Macedonia, which is closely related to the art of Thessaloniki and Constantinople.