In the middle of the lakeside road, that connects Agrinio with Thermo, lies the monastery of Myrtia. It is a very important Byzantine monument with a history of 1000 years, a reputable, historical and artistic center of the region. It is called Myrtia due to its vicinity to the homonymous community. It is built in a magnificent location looking across Lake Trichonida.

In the Holy Narration of the monastery of Prousos, it is reported that in the Monastery of Myrtia “cultivated men who are famous for their virtue never bribed”.

The inscription of 1491 refers to the memory of “The Holy Theotokos and perpetually Virgin Mary of Phaneromeni”, but it is also known as Myrtia monastery.

Saint Cosmas of Aetolia dwelled in the monastery for a while. The buildings of the monastery were destroyed by the German occupation troops in 1943, but the Katholikon, which stands in the center of the courtyard dedicated to the Virgin Mary's Presentation (the Entrance of the Theotokos into the Temple), was rescued. Its visual hagiography (icon painting) includes all the schools of post-Byzantine painting art: the Cretan school, the school of the mainland of Hellas as well as the folk style of art of the 17th and 18th century. The temple is full of frescoes of the 12th and early 13th century. The visual hagiography (icon painting) of the main church was made in 1539.

In the era of the Ottoman domination it was a center of education. The extant relics of the Monastery are “Theotokos Odigitria” and “the Assumption of the Virgin Mary” which are painted with tempera on wood with fabric cover, the Epitaph, the holy vessels and saints’ icons of particular style.

In the 1990s the monastery was reconstructed. It houses three monks and celebrates on November 21 (The Presentation of the Virgin) and on the feast of the chapel of Metamorphosis on August 6.