A unique church is located in Klafsi, an idyllic village. The antique name of the village was “Kallion’’ (meaning in ancient greek good), while its actual name (tears) possibly makes reference to the suffering and weeping of the residents after the destruction of their homeland from the Gauls in 279 B.C. In this village, the early Christian church, built in the 5th or 6th century A.D., is considered to be one of the most ancient monuments in Evrytania. The three-aisled wooden roofed basilica is dedicated to Saint Leonidas, bishop of Athens who was tortured and died in Corinth in 250 A.D. during the prosecution of Christians by Emperor Decius. It was destroyed by fire or earthquake in the middle of the 6th century and discovered in 1956. The archaeological research revealed the extraordinary mosaic floor of its interior that covered almost the entire floor. Geometric and vegetal elements as well as the figure of various animals and eight dedicatory inscriptions that bear information about the monument constitute the mosaic’s decorative motifs.