Within the great precincts of the castle in Niokastro, the visitor will find the Church of the Transfiguration of the Saviour. The building was originally constructed as a mosque (the visitor can clearly understand that from the appearance of the building) to serve the religious needs of the Muslim population.
During the short occupation of Niokastro by the Venetians (1865-1715), the building was converted into a church. In the time period between 1900 and 1930 CE, a campanile was added to the church, which has survived to the present days. Nowadays, the church is under maintenance. Access to the interior of the church is not possible as a series of operations are being carried out for the reinforcement of its walls.