The monastery lies on the west slope of Mt. Helikon, below the acropolis of ancient Steirion. It is enclosed by a wall and comprises two- and three-storeyed blocks of cells, a bell-tower at the SW corner, the Refectory on the south side and the two adjoining churches, at the centre of the enclosure.

The smaller church, dedicated to the Theotocos, was built in the 10th century. It is the earliest known example of the four-column, cross-in-square type, it has a spacious, two-column narthex on the west side and a portico to the west of it. This portico actually connects the two churches.

The famous fresco of Jesus of Navi, discovered in 1965, dates from the 10th century and actually belonged to the facade of this church but was later covered by marble slabs when the wall became an interior wall of the catholicon. The interior of the church is distinguished by the rich sculptured decoration of the templon, the capitals, even the drum of the dome.

The catholicon is the earliest preserved specimen of the octagonal cross-in-square type of church, built in the first half of the 11th century. It has a large, tall cupola with a diameter of 9m. The domed central space is surrounded by two-storeyed constructions which were modelled as cross-vaulted chapels

The walls are veneered with marble slabs and decorated with superb mosaics on the upper part and the upper floor. The mosaics represent the more severe and abstracted style of the Middle Byzantine decorative art from the first half of the 11th century.

The catholicon is built over a large crypt, shaped as a cross-in-square church, with groin vaults forming the roof. It is dedicated to Aghia Varvara and contains three tombs: the one in the north wall is the tomb of Hossios Loucas. The roof and much of the walls are covered with wall paintings, dated to the first half of the 11th century.


The monastery was founded by the hermit Loucas Stereiotis, who lived in the area from 945 A.D. until the day of his death, in 953 A.D. The church of the Theotocos was built while Loucas was alive. He was declared an Hossios of the Orthodox Church and His relics were cept in the church but were later moved to the crypt below the catholicon when this was built.