A detour of the main road Argostoli-Poros leads to the Monastery of Panagia ton Sissia near the sea. Tradition has it that the founder of the monastery is St. Francis of Assisi, the protector of animals and nature, and the name of the monastery as a corruption of the word Assisi.
Another version is that monks of the Franciscan order founded the monastery during the 13 o century.
The Venetians established in 1676 a litany from the monastery in the capital on the day of the feast of St. Mark as a sign of respect for the Most Peaceful Republic. The curious thing is that this initial obligation of the monastery evolved over time into a religious custom. Every year the litany of the icon of the Virgin Mary takes place on the Sunday of Thomas (the first Sunday after Easter) from the monastery of Sissia in Kastro (12 km). The portable icon of the Virgin of the monastery of Sissia remains for three weeks in the church of Evangelistria in the Castle and on the fourth Sunday after Easter (the Sunday of the Paralytic) it is transported again by litany to the monastery.
Its most valuable heirloom The icon of the Virgin of the Standing Hymn was created by the Cretan hagiographer and priest Stefanos Tsagarolas in the year 1700 and is kept in the Ecclesiastical Museum of the Monastery of Agios Andreas.