The Venetian church of Saint Demetrios, located near Kastri Viannou, served as the katholikon of the monastery bearing the same name, which, according to tradition, was built using milk instead of water, hence the name “Galaktoktistos” (built with milk). Today, the cells and other buildings of the monastery are in ruins. The church, adorned with frescoes, is a single-aisled structure with a barrel-vaulted roof, featuring a transverse narthex and entrances on its southern and western sides.
