This church, which is dedicated to the Virgin Mary and Saint John, is located on the north side of the village of Mathia. It is a two-aisled arched church with influences from different architectural phases in each one of two aisles.
The oldest aisle, which is on the south, is dedicated to the Assumption and inside it is decorated by frescoes of the early 14th century that are not well preserved. The north aisle of the church, dedicated to St. John the Baptist, bears murals and is a later addition of the 19th century. It seems to have been built on the ruins of an older temple, as it is demonstrated by the southern part of its walls.