Small in size, it is the only Catholic church on the island. Next to the Solomos and Kalvos Museum it seems to be one and only building due to the fact that they were built with the same architectural style. It was founded in 1518 as a chapel of the Franciscan monk monastery. Later on it was the cathedral of the Latin of Zakynthos-Kefallinia. Today this bishopric has been abolished and St. Mark only operates in the summer. His original form was particularly imposing and his interior decoration precious. Few of his internal exhibits have survived. After the earthquakes, it was rebuilt in smaller dimensions.