The Church of Panagia (Virgin Mary) with the particular name ?Krena? is located in the farmland surrounding the village of Vavyloi in central Chios. It is a monument of exceptional importance, not just for the island of Chios itself, but within Byzantine architectural tradition in general. It shares the same architectural typology as the Katholikon of Nea Moni, namely that of the octagonal church. The main deviation from the prototype of Nea Moni lies in the support of the dome to the east, which here rests on a tall barrel vault. The church is composed of a main church and an inner narthex, which belong to two distinct, though quite close together, building phases in the late 12th century. The two arcosolia found on the north and south walls of the inner narthex suggest that this part of the church was intended to house burials. The ruined outer narthex was added much later, during the 16th century. Part of the main church dome, as well as the small dome and western wall of the inner narthex collapsed during the 1881 earthquake, and were rebuilt in the year 1884.

The surface articulation of the exterior walls of the church is particularly striking due to the multi-colored natural building material, and the intricate shading patterns it creates. The interchange of stone and brick courses, on which the so-called ?recessed-brick? technique is employed, the tall blind arches, the beveled fillet cut cornices, the semicircular pediments, and the rich decorative brick ornamentation (in which no motif is ever repeated on any given facade) are all elements that are commonly found in churches of the so-called ?Constantinople school? architectural tradition. The church facades are further enriched by the integrated marble architectural members, which are either integral parts of the masonry (cornices, column capitals, window mullions, etc), or have been incorporated as spolia within the masonry, and originally belonged to much more antique buildings.

The church interior is completely covered with frescoes which, according to an inscription in the inner narthex, date to slightly earlier than the year 1197. The patrons of the first part of the church were Eustathios Kodratos and his wife Eirene Doukaina Pagomeni, both members of the local aristocracy, and with strong ties to the imperial court in Constantinople. They are depicted on the south arcosolium and on the east wall of the inner narthex. In the bema we find the depiction of Stephanos Pepagomenos, the uncle of Eirene, and bishop of Hypaipa in Asia Minor. On the bema conch there is a depiction of the praying Theotokos, on either side of the triple-light window the Communion of the Apostles, on the Prothesis the Washing of the Feet, and on the Diakonikon the Prayer at Gethsemane. The lower parts of the bema walls are covered with whole-body images of hierarchs and deacons. The original Pantocrator surrounded by angels fresco on the spherical part of the central dome, unfortunately did not survive. The image of the Pantocrator that survives today dated back to 1884, according to an inscription. The dome drum is decorated with whole-body images of Prophets, and the pendentives with images of the four Evangelists, two Seraphim and two Tetramorph angels. Four hierarch busts cover the area below the circular base of the dome. The conches are decorated with scenes from the life of Christ, namely the Presentation, the Baptism, the Transfiguration, the Crucifixion, the Raising of Lazarus, the Entry into Jerusalem, the Resurrection, the Lamentation, and the Noli mi tangere scene. The scene of the Annunciation of the Virgin is depicted on the west wall over the main entrance. Lastly, a multitude of images of military saints and monks line the lower part of the surrounding walls. On the left side of the main entrance we find the allegorical scene of Bios and Kairos (Life and Chance), which dates to the 18th century.

Before the initial 12th c. fresco layer was exposed in the 1980s, the main church was almost completely covered with 1734 frescoes created by Chios painter Michael Chomatzas. The dome drum and the areas between the dome windows were covered with exquisite Late Byzantine frescoes with whole-body images of Prophets. These frescoes have been detached, and are now on display in the Chios Byzantine Museum.

An interesting fresco was detached from the tympanon of the south arcosolium in the inner narthex in order to expose the original 12th c. fresco layer; it portrays a donor who appears to offer a model of the church to Christ, borne by the Theotokos. This image is dated to the early 14th century and depicts the second patron of Panagia Krena, who funded either its renovation, or the newer frescoes of the inner narthex.

The restoration project of the church of Panagia Krena, as well as the conservation of the frescoes were completed under the 3rd Community Support Framework (2000-2006).